Working memory refers to the "workspace" with which we perform mental operations, such as doing mental math. This concept is most in line with cognitive psychology, as cognition refers to mental operations. While there may be aspects of cognition in each of the other choices, those concepts are more likely to be studied by developmental, social, or abnormal psychologists.

The key words in this question concerns "what happens to the brain".

Define the subfields:

Biological analyzes how behaviors and mental processes are shaped by the brain.

Clinical concerns treatment of behavioral and mental disorders among the population.

Developmental examines changes in behavioral and thought processes over time.

Educational is the branch studying learning.

Social examines the relationships between people.

The best answer is biological psychology.

Seligman is best known as a pioneering thinker in the field of positive psychology, or the science of what helps people to thrive. This contrasts starkly with the traditional focus of psychology: on discovering what makes people distressed or unhappy. He is well known for coining the term "learned helplessness," a phenomenon he observed in dogs that also translates to human behavior. 

Albert Ellis studied psychoanalysis but eventually broke from that school of thought and developed rational-emotive therapy, a cognitive approach which stresses that negative thoughts lead to mental disorders like depression. Like Ellis, Aaron Beck began as a psychoanalyst but eventually formed a new approach known as cognitive therapy. Lev Vygotsky took a socio-cultural approach to exploring cognitive development, emphasizing that family relationships and culture play key roles in the development of cognition. Erik Erikson was a personality theorist whose 8-stage psychosocial theory of development across the lifespan has been highly influential.

Tip: When studying influential psychologists, focus on understanding the differences between psychologists whose approaches are most similar, such as Aaron Beck and Albert Ellis. 

Behaviorism believes that psychology can only be accurately studied through the analysis of objective and quantifiable actions and behaviors conducted by a chosen population. While there is, of course, a wide spectrum of behaviorist thinker who consider inner emotional states to various degrees, in the strictest sense behaviorism studies behaviors and actions exclusively

Community psychology focuses on studying the interaction between people and their social environments and how social institutions influence individuals and groups. In this scenario, a community psychologist would observe how the school or area promotes bullying. A community psychologist strives to understand the connection between individuals' contexts with regards to the wider society. By doing so, they try to understand the quality of life in terms of the people, the community, and the society. In this instance, there may be some underlying cause in the community or society that is promoting children to instigate and continue bullying at school by affecting their behavior and attitudes. Comparative psychology would not be the correct answer because this specialization focuses on studying the behavior and mental processes of non-human animals as to shed light on evolutionary and developmental history. Cognitive psychology would be incorrect because this specialization pertains to understanding and observing mental processes such as paying attention, learning, language, memory, and the like. Developmental and evolutionary psychology would also be incorrect choices in that these specializations focus on understanding the changes of human mental processes over time or with respect to natural selection. All options excluding community psychology pertain to understanding behavior or mental abilities such as learning. Given that this bullying incident is not localized to one student, a broader approach would best fit the situation. 

Psychoanalysis, pioneered by Sigmund Freud, focuses on making the unconscious thoughts and motivations of humans become conscious. Treatment based off of this would likely involve methods to expose the unconscious thoughts and motivations of a patient.

The correct answer is "psychodynamic." In this theory, Freud explains how the unconscious drives human behavior through the id, the ego, and the superego. On the other hand, the "behavioral" approach reasons that behavior is a direct respondent of reinforcement. Watson and Skinner famously contributed to this school of thought. The "cognitive" approach emphasizes the process and storage of information in the brain. Piaget and Chomsky are most well known in this school of psychological thought. The "humanistic" approach studies how environmental influences, such as love, determine human outcome in life. Rogers and Maslow are famous contributors to this approach. Last, the "biopsychosocial" approach encompasses all of the other approaches mentioned in these answers. It stems from the idea that biological, psychological and socio-cultural influences affect behavior and thinking.

Human factors psychology applies information on human behavior to design and evaluate various products. This field focuses on maximizing human efficacy by making the easiest to use and safest products for consumers.

"Psychiatrists" are medical doctors (i.e. physicians) who are allowed to prescribe psychopharmacological treatments (e.g. antidepressants) to help aid in treating various psychiatric illnesses. All of the other professions cannot legally prescribe medication.