Answer: A) Needn't have done.
Explanation for this question is being written.
Answer: D) To go.
Answer: D) Say that something happened but wasn't necessary.
Answer: B) Needn't have.
Answer: B) Needn't have done it.
Answer: A) Needn't have put.
Answer: A) Absence of necessity. The action was done, but it was unnecessary.
Answer: A) I needn't have done my homework for Friday.
Answer: B) Needn't have prepared.
Answer: C) Needn't have taken.
Answer: B) You needn't have done it.
Answer: A) Needn't have bought.
Answer: B) Waited
Answer: A) Needn't have cleaned.
Answer: C) Needn't
Answer: D) Needn't have gone / could have saved.
Answer: C) Needn't have put off / should have asked.
Answer: B) In the end, I needn't have bought as much bread as I did.
Answer: D) Needn't have.
Answer: A) Didn't need to show.
Answer: D) I needn't have worried about my job.