Given that −3i is a zero, factor the following polynomial function completely. Use the Conjugate Roots Theorem, if applicable. f(x)=x⁴−3x³−19x²−27x−252
a) (x-3)(x+4)(x²+7)
b) (x+3)(x-4)(x²-7)
c) (x-3)(x+4)(x²-7)
d) (x+3)(x-4)(x²+7)