Fact 1: Lymphocytes are the key cells involved in the immune response. Fact 2: Lymphocytes are produced in the bone marrow. Given the two facts above, where are the key cells involved in the immune response made?
Choose your answer from: a. bloodstream. b. humans. c. mitosis. d. bone marrow. e. organs. f. Epidermis. g. critical organs. h. stomach.
d.