We gain energy from eating plants. plants create energy. this statement is according to the law of thermodynamics.
a) true; first
b) true; second
c) false; first
d) false; second

Option A

The statement is true and its according to first law of thermodynamics.

Explanation:

First law of thermodynamics states that energy cannot be created or destroyed.

Man get energy by eating plants. The plant consume is broken down chemicals bond of carbohydrates to release energy. for cellular activities.

Plant materials are use as energy source when it is degraded by biofermentation.

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.