Question

There were several policemen..........duty. (Choose the correct preposition)

• A. to
• B. on
• C. for
• D. at

Hint:

Use “on” with duty and leave — e.g., “on duty,” “on leave.” Use “at” for location and “in” for state.

Answer 1

The Correct Option is B

Step 1: Understanding the phrase.
The phrase “on duty” means actively working or engaged in one’s official responsibility. The correct preposition with “duty” is “on.”
Step 2: Analyzing the options.
- (a) to: Incorrect; not used with “duty.”
- (b) on: Correct; standard phrase “on duty.”
- (c) for: Incorrect; used for purpose, not state.
- (d) at: Incorrect; used for location, not activity.
Step 3: Constructing the correct sentence.
“There were several policemen on duty.”
Step 4: Grammar Rule.
Common prepositional phrases include “on duty,” “on leave,” “at work,” “in office.”
Step 5: Conclusion.
Hence, the correct preposition is “on.”