b produce and manage movement
Explanation:
nerve cells are there to move muscles, send signals to glands, or register sensory stimuli.
The answer that would best complete the given statement above would be the second option: MUSCLES. Contractile proteins are found in muscles. <span>The muscles themselves contain muscle fibers, each of which contains cylindrical strands of </span>contractile proteins <span>called myofibrils. Hope this answers your question.</span>