The first amendment has often been interpreted as including a) the establishment of a bicameral legislature b) due process c) the reserved powers d) separation of church and state

The answer is d.  
The first amendment only establishes that the government is not allowed to restrict the right to speech, free press, assembly, petition, and most importantly to the free practice of religion. This means that people are free to practice whatever they want to, i.e they are not restricted by the state and the state is not influenced by religion (kind of). The other answers have nothing to do with the first amendment.

It’s either c or d as the answer.

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.