The question is down below.

(c)there is no heat flow between the metal and the oil

Explanation:

oil is not a good conductor of heat

did you fail the test? xd

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.