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': 'Giardia lambia infection is common in: \nSelect and explain. \nA. Selective IgM deficiency, B. Selective IgA deficiency, C. Common variable hypogammaglobulinemia, D. Severe combined immunodeficiency', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Selective IgA deficiency is associate with infections like G. lamblia, hepatitis virus, S. pneumoniae, and H. influenzae Immunodeficiencies and common infections: Selective IgM deficiency: S. pneumoniae, H. influenzae, E. coli Common variable hypogammaglobulinemia: Pneumocystis, Cytomegalovirus, S. pneumoniae, H. influenzae Severe combined immunodeficiency: S. aureus, S. pneumoniae, H. influenzae, Candida albicans, Pneumocystis, Varicella-zoster virus, Rubella virus, Cytomegalovirus Ref: Harrisons principles of internal medicine, 18th edition, Page: 1010.', 'role': 'assistant'}]