Which statement about the difference between autotrophs and heterotrophs is true?

A.
Autotrophs transform radiant energy into chemical energy, but heterotrophs can’t.
B.
Autotrophs take in only oxygen, but heterotrophs take in both oxygen and carbon dioxide.
C.
Autotrophs have two different electron transport systems, but heterotrophs have none.
D.
Autotrophs don’t have a Calvin cycle, but heterotrophs do.