請問一題PP數學，感激

A certain office supply store stocks 2 sizes of self-stick notepads, each in 4 colors:  blue, green, yellow, or pink.  The store packs the notepads in packages that contain either 3 notepads of the same size and the same color or 3 notepads of the same size and of3 different colors.  If the order in which the colors are packed is not considered, how many different packages of the types described above are possible?

(A)  6

(B)  8

(C)  16

(D)  24

(E)  32

答案是C

組合好難喔