Why is ligand binding significant in the initiation of GPCR desensitization?

• A. It inhibits the phosphorylation of GPCRs by BARK.
• B. It decreases the affinity of GPCRs for secondary messengers.
• C. It triggers the phosphorylation of GPCRs by BARK.
• D. It increases the affinity of GPCRs for G proteins.

Answer: (C)