Which statement best evaluates the differences between the RAS and MAPK pathways in RTK signaling?

• A. RAS pathway leads to calcium release, while MAPK pathway leads to DAG production
• B. RAS pathway involves GRB2 and RAS, while MAPK pathway involves RAF, MEK, and ERK
• C. Both pathways result in the activation of protein kinase A
• D. Both pathways involve direct activation of adenylate cyclase

Answer: (B)