You are answering a USMLE-style medical question. Question: Which of the following patient presentations seen in a pediatric immunology clinic is most consistent with a diagnosis of Bruton's agammaglobulinemia? Options: A) A 15-month-old girl who has had repeated otitis media, pneumonia, and progressive clumsiness since beginning to walk in the past three months B) A 10-month-old boy who has had recurrent viral infections as well as hypocalcemia during neonatal period C) A 4-year-old girl who has had repeated oral candidasis in the past nine months D) A 9-month-old boy who has had recurrent otitis media and pneumococcal pneumonia in the past three months Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.