An orange roughy fish is a fourth-level consumer that requires almost ten times the amount of food available from the primary producers in the ecosystem. why isn't more energy available from the primary producers?

a. primary producers are not very efficient and lose most of their energy to the environment.
b. there is too much competition from other fourth-level consumers, leaving very little available to the orange roughy.
c. only a fraction of energy is passed through each level, so there is less available to upper-level consumers.
d. the energy flow is unbalanced and tends to move toward the lower levels.