One primary difference between the male breast and female breast is:
(a) male breast has no ducts.
(b) male breast lacks estrogen and progesterone stimulation.
(c) male breast lacks areola.
(d) male breast tissue is well differentiated from muscles in chest wall.

answer: c

explanation:

in addition to being able to metabolize, grow, digest food, and excrete wastes, what other functions must an organism perform if it is to survive? survival also depends on the ability to maintain one's boundaries, to move, to respond to stimuli, and to reproduce. oxygen is a survival need.