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': 'Heavy chain of IgA is ? \nSelect and explain. \nA. Gamma, B. Mu, C. Delta, D. Alpha', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Alpha Ig G y (gamma)Ig Aa (alpha)IgM 1.1 (mu)Ig D(delta)Ig E e (epsilon)", 'role': 'assistant'}]