"Villianous" means evil or "wicked." The suffix "-ous" means similar to or like, so you can infer that "villainous" means like a villain. "Benevolent" means kind and generous. "Submissive" means obedient or willing to listen and follow the orders of other people. "Toxic" means contaminated and poisonous. "Portly" means stout or overweight.

"Contemptible" means "hateful" or despicable. "Filthy" means dirty or disgusting. "Polite" means well-mannered and well-behaved. "Euphoric" means extremely happy and joyful. "Noteworthy" means important and signficant.

"Dogged" means "stubborn" and unyielding in one's opinion. "Enthusiastic" means lively and excited about something. "Illiterate" means unable to read or write. "Pious" means very religious. "Skeptical" means doubtful or not easily convinced that something is true.

“Discursive” means rambling or lacking order, so "rambling" is the correct answer.  None of the other answers are close in meaning to “discursive”. “Harmful” means damaging. “Exhaustive” means thorough. “Patterned” means decorated with a recurring design. “Modest” means unpretentious or humble.  

"Proficient" means having the ability to do something. The correct answer "capable" also means skilled or being able to do something. The other choices do not have similar definitions: "inauspicious" means unlucky or unfavorable; "vague" means unclear; "wealthy" means having lots of money; and "scrutinized" means closely watched.

"Eccentric" means unconventional or strange, as does the correct answer "peculiar." The other choices do not have similar definitions: "augmented" means increased or improved; "genius" means extremely smart; "moist" means damp; and "timid" means shy.

"Sinister" means evil or criminal, and the correct answer "menacing" means threatening or intimidating. The other choices are not similar to "sinister" or "menacing": "familial" means relating to the family, "unpleasant" means disagreeable, "convoluted" means confusing, and "intimate" means close and personal.

"Feral" means untamed, or "wild."

"Terse" means using very few words in order to make a point. "Concise" means using the minimum amount of words to communicate an idea. Given the similarities in meaning between these words, they are synonyms. While "terse" and "tense" may sound similar, they have different meanings and therefore are not synonyms.

"Spontaneous" is an adjective that means "performed or occurring as a result of a sudden inner impulse or inclination and without premeditation or external stimulus," so we need to pick out a word that means about the same thing - roughly, "unplanned." While "premeditated" might seem like a good answer because like "spontaneous," it has to do with preparation, "premeditated" actually means "thought out or planned beforehand" and often is used to refer to crimes. So, "premeditated" is an antonym of "spontaneous" and is not the word we're looking for. "Extemporaneous," on the other hand, is an adjective that means "spoken or done without preparation," and since it is closest in meaning to "spontaneous," it is the correct answer.