A student council must select a two-person welcoming committee and a threeperson planning committee from among its members. There are exactly 10 ways to select a two-person team for the welcoming committee. It is possible for students to serve on both committees. In how many different ways can a three-person planning committee be selected?
Answer Choices
A. 10
B. 12
C. 15
D. 18
E. 25