A cone of base radius 4 cm is divided into two parts by drawing a plane through the midpoint of its height and parallel to its base. Compare the volume of the two parts.
a) The volume of the upper part is 3 times the volume of the lower part.
b) The volume of the upper part is 2 times the volume of the lower part.
c) The volume of the upper part is equal to the volume of the lower part.
d) The volume of the upper part is half the volume of the lower part.