$\lim _{x \rightarrow 0} \frac{\sqrt{\cos x}-\sqrt[3]{\cos x}}{\sin ^2 x}=$

• A

  $\frac{1}{2}$
• Correct answer
  B

  $-\frac{1}{12}$
• C

  $-\frac{1}{6}$
• D

  $\frac{2}{3}$

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