Blood cells are made in which system? A. muscular system B. skeletal system C. circulatory system D. digestive system

The answer is skeletal system but white blood cells and platelets are made in the skeletal system

Blood cells are made in the skeletal system. Although it may seem to make more sense for the blood cells to multiply within the blood stream itself, there are actually organs that specialize in the formation of blood cells, primarily the bone marrow found in numerous bones throughout the body.