What are two functions of bone marrow stromal cells with respect to B-cell development?
A. Cytokine expression and traps developing B cells in a specific location
B. Recruits macrophages to phagocytize self-recognizing B cells and decreases HSC when no active infection is present
C. Secretes release factors that direct the B cell to the spleen and expresses necessary cytokines
D. Traps developing B cells in a specific location and recruits red bloods to bring oxygen to developing B cells
E. Triggers HSCs to produce more pro-B cells and secretes cytokines to stimulate osteoblast development
Answer: A