"Imperceptible" is an adjective that means "impossible to perceive," so we need to pick out an answer choice that means something like "impossible to perceive." So, "prominent" cannot be the correct answer because one meaning of "prominent" is "situated so as to catch the attention; noticeable," making it an antonym of "imperceptible." "Undetectable," however, is an adjective that means "not able to be detected," and because it is the answer choice closest in meaning to "imperceptible," "undetectable" is the correct answer.

The prefix trans- means across or travel. The word “transverse” means to travel across something in a slanting or diagonal manner. To provide further help, “parallel” means side-by-side; “perpendicular” means intersecting just once, opposite of parallel; “gradient” and “slope” are synonyms of one another and mathematical terms, both mean incline or angle of rising.

"Carn-" means in the flesh, related to the body. “Incarnate” literally means in the flesh; however, it is taken to mean “personified,” which means the epitome of something, the most obvious example of something. To provide further help, “serendipitous” means owed to good fortune; a “synthesis” is a mixture; a “portent” is an omen; “pertinent” means relevant.

"Indeterminate" is an adjective that means "not exactly known, established, or defined." So, we need to pick out an answer choice that means something like "not exactly defined." "Definite," then, cannot be the correct answer, because "definite," which means "clearly stated or decided; not vague or doubtful" or "clearly true or real; unambiguous," is an antonym of "indeterminate," not a synonym. "Unspecified," however, is an adjective that means "not stated clearly or exactly," and because "unspecified" is the answer choice closest in meaning to "indeterminate," "unspecified" is the correct answer.

The word "prescient" means having knowledge of things before they happen. The best choice is "foreknowing," as it shares the same definition as "prescient." Considering the other choices, "do" means perform an act, "science" is knowledge gained from systematic study, and "sentient" means conscious.

The prefix sub- means beneath or under. “Subliminal” means occurring beneath the surface of your understanding; this is closest in definition to “unconscious.” “Conscious” means aware, so “unconscious” means an understanding you are not aware of. “Unconscious” can also mean passed-out. To provide further help, “posthumous” means occurring after death; “outlying” means remote; “remonstrate” means argue, protest; “comparable” means similar, able to be compared. 

“Innocuous” means not harmful, which is identical in definition to “benign.” Here might be a good time to examine the differences between the prefixes "ben-" and "mal-." "Ben-"means good, positive, helpful, etc. and "mal-" means bad, evil, hurtful, etc. “Malevolent” means evil or wicked-natured and “benevolent” means good-natured, while “malfeasant” means exhibiting bad behavior and “malodorous” means bad-smelling.

“Malcontent” means not content, dissatisfied. To provide further guidance, "whimsical" means quirky and silly; "mercurial" means enigmatic and hard to predict; "nostalgic" means having fond memories about the past; "obsequious" means flattering.

"Incredulous" means disbelieving or doubtful of the credibility of something. Thus, the best answer choice is "disbelieving." For instance, if a child gives an incredulous look about whether drinking tea will help his or her cold, it means that the child is doubtful whether the tea can help him or her.

"Unruly" is an adjective that means "disorderly and disruptive and not amenable to discipline or control." So, we need to pick out an answer choice that means something like "disruptive." "Well-behaved" cannot be the correct answer, then, because "well-behaved" is an antonym of "disruptive." "Rowdy," however, is an adjective that means "noisy and disorderly," and because "rowdy" is the answer choice closest in meaning to "unruly," "rowdy" is the correct answer.