“Churlish” means rude, so "rude" is the correct answer. None of the other answers are close in meaning to “churlish”. “Impersonal” means detached. “Blotted” means marked or stained. “Vague” means not clear. “Focused” means fixated or absorbed.

"Renowned" means famous and admired. Similarly, the correct answer "celebrated" means well-known and praised. None of the other choices have similar meanings: "redundant" means unnecessarily repetitive; "oppositional" means working against someone or something; "frank" means direct and honest; and "dense" means thick.

"Shrewd" means astute or clever. The correct answer "sharp-witted" similarly means smart, quick, and clever. The other answer choices do not have similar definitions: "peaked" means pale and sickly; "vivacious" means full of life; miserly means stingy and mean; and competitive means having a strong desire to be the best at everything.

"Querulous" means complaining, whining, or petulant, so "petulant," which means irritable or grouchy, is the correct answer. None of the other answer choices are close in meaning to "querulous": "charming" means delightful; "inquisitive" means curious; "mild" means gentle; and "rambunctious" means rowdy.

"Resolute" means unshakable or stubborn, and the correct answer "adamant" means insistent and determined. The other choices do not have similar definitions: "beginning" means new, "wavering" means unsure, "troublesome" means difficult, and "particular" means choosy.

"Stringent" means severe, tight and rigid, and the correct answer "strict" means inflexibly maintained or exact and precise. The other choices do not have similar definitions: "slender" means thin, "morose" means gloomy, "yielding" means flexible, and "tangible" means able to be felt.

"Quixotic" means impractically hopeful or romantic, and "idealistic" means optimistic, perhaps to the point of being impractical. "Idealistic" is therefore the correct answer. None of the other answers are close in meaning to "quixotic": "melancholy" means sad, "literary" means relating to literature, "artificial" means not derived from nature, not real, or man-made, and "verbose" means wordy.

"Ignoble" means dishonorable or of low character, so "dishonorable" is the correct answer. None of the other answers are close in meaning to "ignoble": “assertive” means confident; “soft” means not hard; “complete,” when used as an adjective, means whole; and “flighty” means erratic or fickle.

"Demure" means reserved or shy, so "shy" is the correct answer. None of the other answers are close in meaning to "demure": “free” means enjoying liberty;“surprising” means unexpected; “energetic” means active or full of vigor; and "rich” means wealthy.

While "unfair" and "unbiased" may look like similar answer choices, they are actually antonyms. Since "evenhanded" means impartial when judging, "unbiased" is its closest synonym amongst the answer choices, as it means fair—specifically, showing no preferences or inclinations towards or against something. So, the correct answer is "unbiased."