<span>the best option is B
the development of more efficient agriculture
The emergence of efficient forms of agriculture especially in Mesopotamia, led to emergence of early city states as food was produced in surplus to feed the town population. it also led to division of labor. this form of agriculture also contributed to sedentary lifestyle and improved nutrition thus explosive population that contributed to city establishments.
</span>
The Quraan was verbally sent down in parts to The Blessed Prophet Muhammad (peace be upon him) by the archangel Gabriel (Jibril) at the age of 40. The Quraan was finally compiled after the Prophets' death at 63 during the ruling of Umar son of Khattab (RA).
Please do NOT quote me on this. I will look further into it if needed.