Which of the following best describes a phosphorylation cascade initiated by protein kinase A?

• A. A series of dephosphorylation events that deactivate proteins in a signaling pathway.
• B. A series of phosphorylation events that activate or deactivate proteins in a signaling pathway.
• C. A process where proteins are degraded to terminate signaling.
• D. A single phosphorylation event that activates a protein permanently.

Answer: (B)