A 6-year-old child presented with a Trendelenburg gait to the OPD. History of progressive muscle weakness and intellectual impairment was present. He had gained head control by the age of 7 months and had staed walking by the age of 18 months. Her child also had trouble in running and going upstairs. Serum CK levels were elevated drastically O/E Lordotic posture Difficulty in standing up from a sitting position X ray spine was also taken. Muscle biopsy from the quadriceps femoris NCV studies were done and were normal. Which of the following protein is involved in the given diagram: -
A B C D