An 8-month-old child presented with reduced appetite, abdominal distension and pain and psychomotor retardation. The child was normal at bih and both parents are normal. O/E: – Hepatosplenomegaly Moderate lymphadenopathy Abnormal posturing of the limbs, trunk, and face Impaired voluntary rapid eye movements Cheery red spot on fundus examination. Bony defects Lymph node-histopathology and electron microscopy. EM findings Which of the following enzymes is most likely deficient in the above disease: –