In a fog means confused and unable to think clearly. 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: In a fog can refer to a situation involving confused and unable to think clearly.
• Story example: A writer may use In a fog when describing a situation involving confused and unable to think clearly.
• Exam example: When a sentence contains In a fog, choose the meaning “confused and unable to think clearly.”