This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetic Basics Of Carcinogenesis, Subject name: Pathology
In the mitogen activated protein kinase pathway, the activation of RAS is counteracted by: 
Select and explain. 
A. Protein kinase C, B. GTPase activating protein, C. Phosphatidyl inositol, D. Inositol triphosphate
B: GTPase activating protein
Answer: B: GTPase activating protein 
Explanation: Activated RAS is present in association with GTP. Enzyme GTPase will degrade GTP to GDP and result in inactivation of ras. Thus, GTPase activating protein will counteract the activation of ras.