This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Erlotinib is used in ? 
Select and explain. 
A. Colon cancer, B. Pancreatic cancer, C. Gall bladder cancer, D. GIST
B: Pancreatic cancer
Answer: B: Pancreatic cancer 
Explanation: Ans. is 'b' i.e., Pancreatic cancer