It is B and I know it because I am in college and I already know about this question so your welcome for helping put
Answer:
<em>Well, Cells of the immune system not only use lymphatic vessels to make their way and T cells mature in the thymus, they both initially develop from bone marrow. B cells are immune cells that function primarily by producing antibodies. structure on the surface of a pathogen that binds to T or B lymphocyte antigen receptors. Hope That Helps!</em>
<em>From Itsbrazts.</em>
An adult sponge reproduces by mitosis, or cell division.