Concept:The official compilation of Hadith began under the guidance of the Umayyad caliph Umar ibn Abdul-Aziz.
Explanation:During the early period after the Prophet’s death, Hadith were preserved mainly through oral memorisation and practice.
As time passed, many companions of the Prophet passed away, and there was growing concern that authentic traditions might be lost.
To prevent this, Umar ibn Abdul-Aziz ordered scholars to collect, verify, and write down the Hadith.
He commissioned renowned scholars such as Ibn Shihab al-Zuhri to carry out this important task.
This effort marked the first systematic and state-supported compilation of Hadith.
Thus, the compilation of Hadith started at the time of Umar ibn Abdul-Aziz.
Answer:B. Umar bu Abdul-Aziz