An old hand means a person with a lot of experience. 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: An old hand can refer to a person with a lot of experience.
• Story example: A writer may use An old hand when describing a person with a lot of experience.
• Exam example: When a sentence contains An old hand, choose the meaning “a person with a lot of experience.”