A nurse is reinforcing teaching with the guardians of a child who has a new diagnosis of Duchenne muscular dystrophy about passive range of motion exercises to prevent contractures. Identify the joint the nurse should use to demonstrate joint hyperextension. (You will find hot spots to select in the artwork below. Select only the hot spot that corresponds to your answer.)

A. (Wrist joint area): The wrist joint is capable of flexion and extension, but it is not the primary joint targeted when demonstrating hyperextension for contracture prevention in Duchenne muscular dystrophy. Passive exercises at the wrist alone do not significantly impact overall limb contracture risk. B. (Elbow joint area): The elbow joint is commonly involved in flexion contractures, but demonstrating hyperextension here carries risk in children with muscular weakness. Care is taken to avoid overstretching fragile muscles; it is not the first joint used to demonstrate safe hyperextension techniques. C. (Thumb joint area/metacarpophalangeal joint): The thumb and fingers are smaller joints that can safely demonstrate hyperextension during passive range-of-motion exercises. Showing hyperextension here allows caregivers to learn proper technique for preventing contractures in distal joints without causing injury to larger, more vulnerable joints affected by Duchenne muscular dystrophy.