Phosphofructokinase, one of the enzymes which regulates the glycolysis pathway, is activated by

Fructose‐2,6‐ bisphosphate

Explanation:

Phosphofructokinase is activated by fructose‐2,6‐ bisphosphate, which is formed from fructose‐1‐phosphate catalyzed by phosphofructokinase II. Thus, the abundance of F6P results in a higher concentration of fructose 2,6-bisphosphate (F-2,6-BP) and hence activated more phosphofructokinase enzyme and its activity.

it's c. (to reduce the greenhouse effect/carbon gasses)