Concept:During the Prophet's lifetime, Hadith was deliberately not written down in order to protect the Qur'an from being mixed with it.
Explanation:The Prophet (S.A.W) feared that if Hadith were written alongside the Qur'an, the two texts might be confused with one another.
The Qur'an is the primary divine revelation and needed to be preserved exactly as it was revealed.
If the Prophet's own sayings were written down at that time, Muslims might not be able to distinguish between the Qur'an and Hadith.
Therefore, the Prophet did not allow the writing of Hadith during his lifetime.
Answer:D. Of fear that it might be mixed up with the Qur'an