Photosynthesis and Cellular Respiration Are Both Complementary and Relatively Balanced,but

Multiple Choice

Photosynthesis and cellular respiration are both complementary and relatively balanced,but early history of life on Earth showed increasing oxygen concentrations.This indicates that

A) both photosynthesis and respiration were occurring at approximately the same levels.
B) neither photosynthesis nor respiration were occurring.
C) the amount of photosynthesis occurring exceeded the amount of cellular respiration.
D) the amount of cellular respiration occurring exceeded the amount of photosynthesis.