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: Microbiology
[{'content': 'A farmer presents with pustules showing gram positive cocci, beta hemolysis, catalase negative. To show it is group A streptococci, which of the following test is done - \nSelect and explain. \nA. Bacitracin, B. Optochin, C. Novobiocin, D. Bile solubility', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]