What is the physiological impact of phosphodiesterase inhibitors on cyclic GMP levels?

• A. Phosphodiesterase inhibitors increase cyclic GMP levels, leading to enhanced smooth muscle relaxation.
• B. Phosphodiesterase inhibitors increase cyclic AMP levels, leading to enhanced smooth muscle contraction.
• C. Phosphodiesterase inhibitors decrease cyclic GMP levels, leading to reduced smooth muscle relaxation.
• D. Phosphodiesterase inhibitors decrease cyclic AMP levels, leading to reduced smooth muscle contraction.

Answer: (A)