This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'In utero infecion leads to which immunoglobulin? \nSelect and explain. \nA. IgG, B. IgA, C. IgM, D. IgD', 'role': 'user'}, {'content': "Answer: C \nExplanation: IgM antibodies do not pass across the human placenta .Demonstrating IgM antibodies in a patient's serum indicates recent infection, or in a neonate's serum indicates intrauterine infection. Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pg:99", 'role': 'assistant'}]