The correct answer is: A. had heard
The sentence “Everything he told me, I had heard before” is in the past perfect tense. The past perfect tense is used to talk about something that happened before another event in the past. In this case, the event that happened before is “he told me everything.” The event that is being talked about is “I had heard it before.”
The other options are incorrect because they are not in the past perfect tense. Option B, “heard,” is in the simple past tense. Option C, “have heard,” is in the present perfect tense. Option D, “have been heard,” is in the passive voice.
Here is a diagram that shows the time order of the events in the sentence:
- He told me everything. (past)
- I had heard it before. (past perfect)
I hope this explanation is helpful! Let me know if you have any other questions.