Choose the correct statement regarding the use of the complex conjugate pairs theorem.
A) If a complex number a + bi is a zero of a third-degree polynomial with real coefficients, the polynomial must have exactly one real zero.
B) If a complex number a + bi is a zero of a polynomial function, then its conjugate a - bi must also be a zero regardless of the coefficients of the polynomial.
C) In order to use the complex conjugate pairs theorem, the coefficients of the polynomial function must be integers.
D) If a complex number a + bi is a zero of a fourth-degree polynomial function with real coefficients, then the polynomial must have exactly one real zero.