<prompt> Which of the following best describes muscle B compared with muscle A?Adapted for rapid contractionComposed of larger muscle fibersFewer mitochondriaInnervated by smaller nerve fibers  <response>: Muscle B is characteristic of a slow-twitch muscle type 1 composed of predominantly slow-twitch muscle fibers. These fibers are smaller in size and are innervated by smaller nerve fibers. They typically have a more extensive blood supply, a greater number of mitochondria, and large amounts of myoglobin, all of which suppo high levels of oxidative phosphorylation. 