This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
[{'content': 'An anti-hypeensive drug that causes positive coomb&;s test is \nSelect and explain. \nA. Methyldopa, B. Clonidine, C. Hydralazine, D. Sodium-nitropruside', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Alpha-methyldopa causes autoimmune hemolytic anemia Coombs test detects antibodies against foreign red blood cells. (REF. ESSENTIALS OF MEDICAL PHARMACOLOGY K.D TRIPATHI-6th edition. Page No-547)', 'role': 'assistant'}]