"Insolent" means exhibiting disrespectful behavior or speech. "Rude" means showing a lack of politeness. Given that politeness is a sign of respect, "insolent" and "rude" are very close in meaning. They are therefore synonyms.

"Supercilious" means looking down on others, or haughty. To be "scornful" means seeing others as being of less value than oneself. These two words are very similar in meaning and therefore synonyms. The other answer choices are unrelated.

"Prodigal" means spending money in a carefree and reckless way. Thus, "imprudent" (which means not prudent or not careful or wise with one's resources) is the best synonym. (e.g. "The prodigal daughter bought whatever her heart desired, knowing that her relatives would continue to fund her spending habits.")

"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.