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
[{'content': 'Which of the following anticancer drugs are competitive inhibitors of tyrosine kinase? \nSelect and explain. \nA. Imatinib and Sunitnib, B. Letrozole, C. Bicalutamide, D. Fulvestrant', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]