A case in point means a clear example that proves or explains something. 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 case in point can refer to a clear example that proves or explains something.
• Story example: A writer may use A case in point when describing a clear example that proves or explains something.
• Exam example: When a sentence contains A case in point, choose the meaning “a clear example that proves or explains something.”