If the function $y=\sin x(1+\cos x)$ is defined in the interval $[-\pi, \pi]$, then $y$ is strictly increasing in the interval

• A

  $\left(-\pi,-\frac{\pi}{3}\right) \cup\left(\frac{\pi}{3}, \pi\right)$
• B

  $\left(\frac{\pi}{6}, \frac{\pi}{2}\right)$
• Correct answer
  C

  $\left(-\frac{\pi}{3}, \frac{\pi}{3}\right)$
• D

  $\left(-\pi,-\frac{\pi}{6}\right) \cup\left(\frac{\pi}{6}, \pi\right)$

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