Explanation:
that is really easy, when you have the function in such a factorial form already.
the zeros of the whole function are the x values that turn at least one factor to 0 (as when one factor is 0, then the whole expression is 0).
so, you get a zero, when x = 7, or x = 3, or x = 2.
because then either x-7 or x-3 or x-2 is 0.
therefore, C is the right answer.