複選題42. Which of the following statements about the gut-associated lymphoid tissue are true? (A) The normal maturation of the intestinal mucosa and the gut-associated lymphoid tissue is initiated at birth by colonization of the intestines by the commensal microbiota. (B) In the intestines of germ-free mice, Peyer's patches develop normally, and isolated lymphoid follicles are present. (C) Type 3 innate lymphoid cell subset is instrumental in organizing development of the gut-associated lymphoid tissue. (D) At maturity, the intestines maintain the largest number and diversity of commensal microbes in or on the body.