Energy in most ecosystems must flow through autotrophs because
a. only autotrophs can convert solar energy into chemical energy
b. autotrophs are simpler organisms than heterotrophs
c. heterotrophs only generate a small fraction of their energy from photosynthesis.
d. all of the above

Option A

Explanation:

Only autotrophs have the ability to convert solar energy into chemical energy by the process known as photosynthesis. The autotrophs can trap all the radiant energy and only 10% of total energy that autotrophs have is transferred to another tropic level.

The energy from the producers are transferred to the herbivores and 10% of the total energy the herbivores have is transferred to another levels.

So, the energy flow takes place through the autotrophs because only they have the ability to perform photosynthesis.