Similarly, there are a number characteristics that vary between marsupials and placentals. However, there is one characteristic that links both. What is it?
a. they both have milk glands for thermoregulation
b. they both have completely developed young at birth
c. they have an equal distribution on all of the contents
d. they both have a stiff torso that limits hind limb movement during running
e. they both have a placenta to nourish their young
