The correct answer is: E. reluctant, disappoint.
The word “reluctant” means “unwilling or hesitant to do something.” The word “disappoint” means “to fail to meet the expectations of (someone).” In this case, the speaker is saying that he granted the request because he was unwilling to disappoint his friend. He may have not wanted to hurt his friend’s feelings, or he may have felt obligated to help his friend.
The other options are incorrect because they do not accurately describe the relationship between the speaker and his friend. Option A, “bound, hurt,” is incorrect because the speaker is not obligated to hurt his friend. Option B, “destine, agonise,” is incorrect because the speaker is not destined to cause his friend pain. Option C, “sure, displease,” is incorrect because the speaker is not sure that he will displease his friend by granting the request. Option D, “unwilling, please,” is incorrect because the speaker is willing to please his friend, but he is reluctant to do so.
In conclusion, the correct answer is E. reluctant, disappoint.