An ice-cream novelty item consists of a cup in the shape of a 4-inchtall frustum of a right circular cone, with a 2-inch-diameter base at the bottom and a 4-inch-diameter base at the top, packed solid with ice cream, together with a solid cone of ice cream of height 4 inches, whose base, at the bottom, is the top base of the frustum. What is the total volume of the ice cream, in cubic inches?
Answer Choices
A. 8 \pi
B. \dfrac{28 \pi}{3}
C. 12 \pi
D. 14 \pi
E. \dfrac{44 \pi}{3}