3) Which is not true? a) if f(x) is a polynomial function such that f(c)=0, then x-c must be a factor of f(x) b) if x^2 +c^2 is a factor of a polynomial f(x), then f(c)=0 c) if (x-c)^2 is a factor of a polynomial f(x), then f(c)=0 d) if x-c is a factor of a polynomial f(x), then f(c)=0 Thanks!