List the following structures in order from smallest to largest.
(1) Muscle fiber
(2) Myofilament
(3) Myofibril
(4) Muscle fascicle

A) 4, 2, 3, 1
B) 2, 1, 4, 3
C) 3, 1, 4, 2
D) 2, 3, 1, 4
E) 1, 2, 3, 4

The correct order from smallest to largest is: Myofilament (2), Myofibril (3), Muscle fiber (1), Muscle fascicle (4). Myofilaments are the smallest structures, consisting of actin and myosin proteins that form the contractile units within muscle cells. Myofibrils are made up of many myofilaments and are the basic rod-like units of a muscle cell. Muscle fibers are composed of many myofibrils, making them larger in size. Finally, muscle fascicles are bundles of muscle fibers, making them the largest structure listed.