Answer:
a. p(7) = 0.
If x + 7 is a factor of a polynomial p(x), then p(x) must be divisible by x + 7. This means that the remainder when p(x) is divided by x + 7 must be zero. Since the remainder when a polynomial is divided by x - a is equal to p(a), we must have p(7) = 0. Therefore, statement (a) is true, and the other statements are not necessarily true.