How does Merrill Matthews justify continuing the Electoral College?

“Because the states created the federal government, the Constitution gives the states, not individuals, the right to choose the president. Thus the states decide how their electors are chosen and function.”

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.