( A ) Thymosins play a major role in the differentiation of B-lymphocytes, which provide cell-mediated immunity.
( B ) The thymus gland is a lobular structure located on the ventral side of the heart and the aorta.
( C ) The thymus secretes the glycopeptide hormones called thymosins.
( D ) Thymosins also promote production of antibodies to provide humoral immunity.
