Answer:
(A) Grasshoppers are primary consumers.
Explanation:
A food chain is the chain of different organisms in which one organism is being eaten by others. In every food chain consists of producers and different consumers such as primary, secondary and tertiary or top consumers. In the given prairie ecosystem, the tall grasses are producers. The grasshopper feeds on the grass so they are the primary consumers and the mice is eaten by mice, so it is secondary consumers.