In a food chain, if 50,000 calories of energy are in the Ferns. How many calories of energy will be available for the fish, which are the secondary consumers?

500 calories

Explanation:

If ferns are primary producers and they only get 50000 calories then the next level of the food pyrimid will only get 1o percent of that.  Next come primary producers which would get 10 percent of what the primary consumers would get so they would get 5000 calories. Next would be the secondary consumers which is the fish. they would get 10 percent of what the primary producers get so they would only be receiving 500 calories. I HOPE THIS HELPS

i think that the best answer would be c.

tell me if im wrong : )

the answer will be a) proteins i believe