Concept:Hadith 16 of an-Nawawi teaches the importance of controlling one's anger.Explanation:A man asked the Prophet (peace and blessings be upon him) for advice.The Prophet replied, "Do not become angry."When the man repeated his request, the Prophet gave the same advice again.This shows that avoiding anger is a major moral lesson in Islam.It does not focus on unnecessary questioning or having good intentions.Answer:D. ability to control anger