What is the correct sequence of activation in the MAP kinase signaling pathway?

• A. MAP kinase kinase, MAP kinase kinase kinase, MAP kinase
• B. MAP kinase, MAP kinase kinase, MAP kinase kinase kinase
• C. MAP kinase kinase kinase, MAP kinase, MAP kinase kinase
• D. MAP kinase kinase kinase, MAP kinase kinase, MAP kinase

Answer: (D)