Which of the following words is the antonym of the word ‘Auspicious’ ?

Auspicious means favourable, promising, or a sign of good fortune. Its antonym is Ominous, which means threatening or foreboding something bad. So C is correct, and it is the only option that carries the sense of a bad omen.

• Optical (A) relates to sight or lenses. It has no connection to good or bad fortune.
• Oracular (B) means prophetic or mysterious, like an oracle. It describes the manner of speech, not the sign itself, so it is not the opposite of auspicious.
• Austere (D) means severe, plain, or self-disciplined. It describes a person or style, not an omen.

The core concept here is antonym recall through connotation. Good vocabulary for UPPSC language papers is built by linking each word to its emotional sense, and the same skill helps in precis writing and in reading the tone of a passage in Mains General Studies and Essay papers.

Trap: Aspirants often pick Oracular because prophecy sounds like a positive sign. Check whether the word describes the omen itself or only the way someone speaks.