I WILL NAME BRAINLIEST It is believed that the Indus civilization was very large because .
A.
they built a sophisticated road system
B.
the valley is in both India and Pakistan
C.
hundreds of miles separated major cities
D.
they constructed a widespread irrigation system

D.

Explanation:

b

Explanation:

Another possible reason for the fall of the Indus is a lack of resources. The Indus civilization had grown large, and they relied on the wood from the trees in the region.

the correct answer is the following is a list of inventions made in the medieval islamic world, especially during the "islamic golden age" (8th to 13th centuries),[1][2] as well as the late medieval period, especially in the emirate of granada and the ottoman empire.

science and technology in the islamic world adopted and preserved knowledge and technologies from contemporary and earlier civilizations, including persia, india, china, and greece-roman antiquity, while making a number of improvements and innovations.