Who was laughing at you?
Who had been laughing at you?
Who laughed at you?
Who was laughed at by you?
Answer is Right!
Answer is Wrong!
The correct answer is C. Who laughed at you?
A. Who was laughing at you? is incorrect because it is in the passive voice. The question is asking who did the speaker laugh at, not who was laughing at the speaker.
B. Who had been laughing at you? is incorrect because it uses the past perfect tense. The question is asking who the speaker laughed at, not who had been laughing at the speaker.
D. Who was laughed at by you? is incorrect because it is in the passive voice. The question is asking who the speaker laughed at, not who was laughed at by the speaker.
In this case, the speaker is laughing at someone else. The speaker is not being laughed at.