Why is GTPase activity in the G protein alpha subunit important?

• A. It phosphorylates GDP to GTP, activating the signaling pathway.
• B. It hydrolyzes GTP to GDP, leading to the reassociation of the G protein subunits and termination of the signal.
• C. It converts ATP to cAMP.
• D. It binds to adenylate cyclase and inhibits its activity.

Answer: (B)