Systematic desensitization is the best answer as it is a behavioral technique that is most often used to extinguish a phobia. Counterconditioning and aversive conditioning are also behavioral forms of therapy; however, they are not the most successful ways of extinguishing phobias. Self-actualization is a humanistic form of therapy. 

Ben's technique is indicative of "flooding," which pushes the client to address their most frightening scenario first. This induces great anxiety; however, after nothing life threatening happens, the client will realize that their fear is irrational. This is the opposite of systematic desensitization, which starts with a stimulus which induces low anxiety and then builds onward to higher anxiety inducing stimuli. 

"A psychiatrist can prescribe medication" is the correct answer. Psychiatrists can prescribe medication to individuals whom they believe have some sort of chemical imbalance or other psychological disorders. On the other hand, counseling psychologists only need a graduate degree in psychology. Last, "a psychiatrist is trained in Freudian methods" is false because psychoanalysts are trained in Freudian theory. 

"Electroconvulsive therapy" is a procedure in which small electric currents are passed through the brain to trigger a seizure. This procedure is only used to treat very serious illnesses (e.g. severe depression, schizophrenia), not ADHD. All of the other answer choices demonstrate some efficacy in treating those with ADHD. 

Humanistic psychology emphasizes an individual's inherent drive towards self-actualization and creativity. "Unconditional positive regard" is the basic acceptance and support of a person regardless of what the person says or does. Humanistic therapists use unconditional positive regard to establish a strong connection with their clients. 

Positive reinforcement is a behavior-management strategy. The goal of positive reinforcement is to give something to someone to make a desirable behavior more likely to occur in the future. For example, a dog is more likely to obey his owner when he receives his favorite bone.

Gestalt therapy, developed by Fritz Perls, combines the psychoanalytic emphasis of bringing unconscious feelings to immediate awareness and the humanistic emphasis of getting in touch with one's feelings. This therapeutic approach aims to "help people take responsibility for their actions and feelings."

Homework is an important part of some therapeutic styles and is most closely associated with "cognitive behavioral therapy" (CBT). As the question suggests, it involves asking the patient to put in extra work on a certain area of treatment outside of the actual therapy session. Examples of homework include: recording automatic negative thoughts, monitoring stress levels at specific times throughout the week, reading a brief manual about how a certain aspect of therapy works, etc.

Lithium is the most widely used and studied medications for bipolar disorders. They also have a role in treating depression and mania, acutely and long term. Once ingested, lithium becomes prevalent in the central nervous system (CNS), and can bind to a number of receptors in order to block norepinephrine production. It can also interact with neurotransmitters in order to cause a release of seratonin. 

Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat mood disorders. The other choices are used for other types of mental illnesses.