How many students said they participated in both sports and music programs?

A college recruiter interviewed 18 potential students about their interests. Ten students said they participated in sports and 12 in music programs. All said they participated in at least one of these programs, and some participated in both.

How many students said they participated in both sports and music programs?
A . 14
B . 8
C . 6
D . 4
E . 2

Answer: D