This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
[{'content': 'Recurrent Giardiasis is associated with: \nSelect and explain. \nA. Severe combined immunodeficiency, B. Common variable immunodeficiency, C. Digeorge syndrome, D. C8 deficiency', 'role': 'user'}, {'content': "Answer: B \nExplanation: Common variable immunodeficiency is associated with the deficient production of antibodiesThey have a normal number of B lymphocytes but fail to mature into plasma cellsResults in hypogammaglobulinemia, with a reduction in all classes of Ig but sometimes only IgG is reducedVarious disorders associated:Intestinal disorders:Chronic giardiasisIntestinal malabsorptionAtrophic gastritis(with pernicious anaemia)Chronic pulmonary infections:bronchiectasisOthers:can also present with signs and symptoms of lymphoid malignanciesfeverweight lossanaemiasplenomegalylymphadenopathy(ref: Harrison's 18/e p1849, 2059)", 'role': 'assistant'}]