This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Diagnosis of x linked agammaglobulinamia should be suspected if \nSelect and explain. \nA. Absent tonsils and no palpable lymph nodes on physical examination, B. Female sex, C. High iso hemagglutinin titers, D. Low CD3', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref Robbins 9/e p240-241 Classically, this disease is characterized by the following: * Absent or markedly decreased numbers of B cells in the circulation, with depressed serum levels of all classes of immunoglobulins. The numbers of pre-B cells in the bone marrow may be normal or reduced. * Underdeveloped or rudimentary germinal centers in peripheral lymphoid tissues, including lymph nodes, Peyer patches, the appendix, and tonsils * Absence of plasma cells throughout the body * Normal T cell-mediated responses', 'role': 'assistant'}]