Oxygen Diffuses from Blood into Cells Down Its Concentration Gradient

Oxygen diffuses from blood into cells down its concentration gradient. As cells become more active and oxidative phosphorylation increases in the cell, which of the following occurs?

A) The concentration gradient for oxygen increases and oxygen movement into the cell decreases.
B) The concentration gradient for oxygen and its rate of movement into the cell do not change.
C) The concentration gradient for oxygen increases and oxygen movement into the cell increases.
D) The concentration gradient for oxygen decreases and oxygen movement into the cell decreases.
E) The concentration gradient for oxygen decreases and oxygen movement into the cell increases.