Antonyms

Nefarious means evil or wicked and the opposite to this is respectable.

Ruthless means without pity or compassion.

Negligent means lazily careless.

A 'roar' is a loud, deep, or powerful sound. Its opposite would be a soft or quiet sound, making 'whisper' the correct antonym. 'Seamless' means smooth/uninterrupted, 'wheedle' means to persuade flatteringly, and 'sinner' is a moral judgment - none are sound-related opposites.

Rugged means unpolished.

Ruffle means to destroy the smoothness or evenness.

Salient means most noticeable or important.

Rout means to a defeat attended with disorderly flight. Triumph refers to a victory.

Morality is conformity to the rules of right conduct. Profanity is blasphemous or obscene language.

This asks for the opposite of catapult. Catapult means to hurl or launch something forcefully forward or upward. The opposite would be a downward movement or failure. Option B (Downfall) correctly represents the opposite in terms of direction and success.

This asks for the opposite of enigmatic (mysterious, puzzling, difficult to understand). Option D (Straightforward) correctly represents the opposite - something clear, direct, and easy to understand. Options A, B, and E are all synonyms (or near-synonyms) of enigmatic, not antonyms.

This asks for the opposite of opaque (not transparent, cloudy, or unclear). Option C (Transparent) is the direct antonym - something that allows light to pass through clearly. Options A and E are actually synonyms of opaque, not antonyms.

Sanctimonious means making a show of being virtuous or morally superior, often hypocritically. Humble is the opposite as it represents genuine modesty without pretense. Smug and Pious are actually similar to sanctimonious, not opposites. Callous means unfeeling, which is unrelated to the concept.

Piquant means engagingly stimulating, provocative to the taste or interest - something with a sharp, lively quality. Bland is the perfect opposite as it means lacking flavor, dull, or uninteresting. Tangy is actually a synonym for piquant, while Blunt, Rigorous, and Shocking are not relevant opposites.

Munificent means extremely generous, liberal in giving. Greedy is the opposite as it represents excessive desire for more and unwillingness to share. Bountiful and Unsparing are synonyms of munificent, while Liberal is also similar. Rudimentary means basic/elementary, which is unrelated to generosity.