Why did the Nile have an advantage over the Tigris and Euphrates? What made it better?

Ithink the answer is b

The answer is c, i, iii, and iv. this is because farming and mining deal with harvesting raw materials, construction work falls under manufacturing, and piloting a plane is a service. ii is wrong because making bread is using  raw materials to produce goods, which would fall under the secondary sector, not primary.

Temperature, rainfall and relative humidity.

The area of the indian subcontinent is 4.4 million km^2 whereas the usa is  9.8 million  km²