<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:An 18-month-old boy is brought to the physician because of a 2-day history of cough, fever, and lethargy. He has been admitted to the hospital twice during the past year for pneumonia. He can stand without support but has not started to walk. He speaks in bisyllables. He is at the 3rd percentile for height and 4th percentile for weight. Examination shows diffuse crackles over bilateral lung fields. Abdominal examination shows hepatosplenomegaly. Fundoscopy shows bright red macular spots. Despite being given appropriate antibiotic therapy, the patient dies. A photomicrograph of a section of the spleen obtained during autopsy is shown. Accumulation of which of the following substances is the most likely cause of this patients condition?? A: Limit dextrin, B: Sphingomyelin, C: Ceramide trihexoside, D: Cerebroside sulfate, E: Glucocerebroside,  <response>: This is a medical question asking about the likely cause of a condition in an 18-month-old boy based on his symptoms and autopsy findings. The key details are his recurrent pneumonia, failure to thrive, developmental delays, hepatosplenomegaly, retinal abnormalities, and the photomicrograph of his spleen. This constellation of findings is most consistent with Niemann-Pick disease, a lysosomal storage disorder caused by deficiency of sphingomyelinase leading to accumulation of sphingomyelin in tissues. The photomicrograph shows foamy macrophage infiltration of the spleen, a classic finding in Niemann-Pick disease. Of the answer choices, sphingomyelin accumulation is most consistent with Niemann-Pick disease pathology.B: Sphingomyelin 