If $p, q, r$ are positive integers and $\omega$ is the cube root of unity and $f(x)=x^{3 p}+x^{3 q+1}+x^{3+2}$, then what is $f(\omega)$ equal to?

• A

  $\omega$
• B

  $-\omega^2$
• C

  $-\omega$
• Correct answer
  D

  $0$

Hence, the correct answer is option: 'D'.