6. Which of the following correctly indicates the hierarchy of skeletal muscle organization from "small" to "big"?
(A) muscle fiber, sarcomere, myofibril, motor unit
(B) myofibril, sarcomere, motor unit, muscle fiber
(C) sarcomere, myofibril, muscle fiber, motor unit
(D) myofibril, sarcomere, muscle fiber, motor unit
(E) sarcomere, muscle fiber, myofibril, motor unit