Answer:
The correct answer is myofibrils
Step-by-step explanation:
The fundamental part of the muscle cytoskeleton is made up of myofibrils that are the contractile elements of skeletal muscle cells.Muscle fibers are made up of myofibrils, membranes, and cytoskeletal networks that anchor contractile fibrils to the sarcolemma. Myofibrils are composed of repeating contractile units known as sarcomeres and are perhaps the most ordered macromolecular structures in eukaryotic cells. Myofibrils are made up of actin and myosin filaments that are large polymerized protein molecules responsible for actual muscle contraction.