Which one of the following statements regarding enzyme inhibition is correct?

Options

A. Non-competitive inhibition of an enzyme can be over come by adding large amount of substrate
B. Non-competitive inhibitors often bind to the enzyme irreversibly
C. Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein
D. Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme