A passing fancy means a short-lived interest. This answer is correct because the expression has a fixed figurative meaning in English. In an SSC idiom question, students should match the whole phrase with its accepted meaning rather than translate each word separately.

• Classroom example: A passing fancy can refer to a short-lived interest.
• Story example: A writer may use A passing fancy when describing a short-lived interest.
• Exam example: When a sentence contains A passing fancy, choose the meaning “a short-lived interest.”