The glycolytic pathway oxidizes glucose to two molecules of pyruvate and also produces a net of two molecules of atp. atp allosterically inhibits the enzyme, pfk-1, that catalyzes the third step of glycolysis. this is an example of
a. competitive inhibition
b. feed-forward activation
c. negative cooperativity
d. feedback inhibition

D.  Feedback inhibition

Explanation:

Feedback inhibition is one of the processes that regulate the multi-step metabolic pathways in the cells. Here, the end product of the pathway inhibits one or more regulatory enzymes. Inhibition of regulatory enzymes slows down all the subsequent steps of the pathway.  

In the given example, ATP (one of the final product of glycolysis) inhibits the enzyme phosphofructokinase-1 which in turn would inhibit all the 7 subsequent steps of the glycolysis.  

Here, a buildup of one of the end products of the pathway slows down the entire pathway. So, it represents feedback inhibition.