ATP:
A. inhibits activity of phosphofructokinase (PFK) allosterically
B. activates activity of phosphofructokinase (PFK) allosterically
C. inhibits activity of phosphofructokinase (PFK) hormonally
D. activates activity of phosphofructokinase (PFK) hormonally
E. does not alter phosphofructokinase (PFK) activity