Answer:
Peyer's patches: b) site of B cell maturation
Step-by-step explanation:
B lymphocytes are produced in the bone marrow and get mature in the bone marrow only so the site of B cell maturation is bone marrow, not Peyer's patches. B cells produce antibodies that help in destroying microbes.
Peyer's patches are lymphatic tissue mass which is found especially in the mucosa and submucosa of the ileum. This lymphoid organ has a large number of B lymphocytes which monitors the intestinal bacteria and prevents the growth of pathogenic bacteria in the intestine.