What is the mountain ridge between the black and caspian sea?

The caucuasus mountain range cuts through the area between the black and the caspian seas. the caucasus mountain range runs through georgia, azerbaijan, armenia, and parts of russia.

Answer decreased soil salinity;

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.