In a $\triangle A B C, 2 A+C=300^{\circ}$. If the circumradius of the $\triangle A B C$ is eight times its inradius then $\sin \frac{C}{2}=$

• A

  $\frac{1}{2}$
• Correct answer
  B

  $\frac{1}{4}$
• C

  $\frac{3}{4+\sqrt{3}}$
• D

  $\frac{1}{\sqrt{2}+1}$

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