<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 12-year-old boy is brought to the physician because of difficulty in walking for 5 months. His mother reports that he has trouble keeping his balance and walking without support. Over the past year, he has started to have difficulty seeing in the dark and his hearing has been impaired. Examination shows marked scaling of the skin on the face and feet and a shortened 4th toe. Muscle strength is 35 in the lower extremities and 45 in the upper extremities. Sensation to pinprick is symmetrically decreased over the legs. Fundoscopy shows peripheral pigment deposits and retinal atrophy. His serum phytanic acid concentration is markedly elevated. The patients condition is most likely caused by a defect in which of the following cellular structures?? A: Peroxisomes, B: Mitochondria, C: Smooth endoplasmic reticulum, D: Myofilaments, E: Proteasomes,  <response>: This is a clinical vignette describing a 12-year-old boy with progressive difficulty walking and impaired vision and hearing over the past year. The key findings on exam are scaling of the skin, shortened 4th toe, decreased muscle strength, decreased sensation, retinal changes, and elevated serum phytanic acid. The clinical presentation is most consistent with Refsum disease, which is caused by a defect in peroxisomal beta-oxidation of phytanic acid. This results in accumulation of phytanic acid and a variety of neurological and other clinical manifestations. The retinal changes and elevated phytanic acid point towards a peroxisomal disorder rather than mitochondrial, endoplasmic reticulum, myofilament, or proteasome abnormalities.A: Peroxisomes 