Concept:The first official effort to compile Hadith was initiated during the reign of a pious Umayyad caliph.
Explanation:Caliph Umar b. Abdul-Aziz, also known as Umar II, ordered the official collection of Hadith.
He instructed scholars to gather and write down the sayings and actions of Prophet Muhammad (SAW).
This was done to preserve the Sunnah from being lost or mixed with false reports.
Before his order, Hadith were mostly memorized and transmitted orally.
His directive marked the beginning of formal, written Hadith literature.
Therefore, among the given options, the correct facilitator is Caliph Umar b. Abdul-Aziz.
Answer:D. Caliph Umar b. Abdul-Aziz