The carbon cycle is
a. another name for the Calvin cycle of photosynthesis.
b. the fixation of carbon by photosynthesis then the regeneration of carbon dioxide by cellular respiration.
c. the cycle of carbon in a phospholipid in a chloroplast to a phospholipid in a mitochondrion and back to the chloroplast again.
d. the cycling of ATP to ADP and Pi and then back to ATP.
