D is the answer hope it helps
Type IIx<span> are best known as </span>fast-twitch muscle<span> fibers. These are the muscle fibers primarily responsible for fast, </span>explosive<span> movements like sprinting. However, they lack the endurance-boosting ability of </span>slow-twitch fibers<span> and can only be used for </span>short<span> periods of time</span>
Antibody production is carried out by specialized A. B-cells<span>.
B lymphocytes specialize to form a specific antibody. When the specific antigen to which the antibody is compatible with is present, the B lymphocyte that produces that specific antibody divides rapidly. A large number of clones are produced, which all produce the antibody and destroy or deactivate the antibody.</span>
