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: Pathology
[{'content': 'The commonest type of pericarditis in acute rheumatic fever is - \nSelect and explain. \nA. Serous, B. Fibrinous, C. Serofibrinous, D. Purulant', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Fibrinous", 'role': 'assistant'}]