Which is a glacial feature caused by erosion? a. glacial erratics b. moraines c. striations d. terminal moraines

The correct answer is A. Glacial erratics.

Glacial erratics is a term used to define the pieces of rocks that differ in shape and size from the native rocks, in the area where they rest. These rocks are dragged from their primary position by the glacial ice, very often over distances of hundreds of kilometers. 

Well, a and b together would be negative. b alone would also be negative.

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.