What is the downstream effect of G protein activation on adenyl cyclase?

• A. Adenyl cyclase is inhibited, preventing cyclic AMP production.
• B. Adenyl cyclase synthesizes GDP, maintaining G protein activity.
• C. Adenyl cyclase is degraded, reducing signal transduction.
• D. Adenyl cyclase is activated, leading to the production of cyclic AMP.

Answer: (D)