By leaps and bounds means very quickly and greatly. 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: By leaps and bounds can refer to a situation involving very quickly and greatly.
• Story example: A writer may use By leaps and bounds when describing a situation involving very quickly and greatly.
• Exam example: When a sentence contains By leaps and bounds, choose the meaning “very quickly and greatly.”