How does Le Chatelier's principle explain the effect of competitive inhibitors on enzyme reactions?

• A. Competitive inhibitors increase the concentration of enzyme-substrate complex, causing the equilibrium to shift right.
• B. Competitive inhibitors increase the concentration of free enzyme, causing the equilibrium to shift right.
• C. Competitive inhibitors have no effect on the equilibrium of enzyme reactions.
• D. Competitive inhibitors decrease the concentration of free enzyme, causing the equilibrium to shift left and decrease enzyme affinity for the substrate.

Answer: (D)