If $y=\left(\operatorname{Sin}^{-1} x\right)^2$, then $\left(1-x^2\right) \frac{d^2 y}{d x^2}-x \frac{d y}{d x}=$

• A

  $\frac{1}{2}$
• Correct answer
  B

  $2$
• C

  $-\frac{1}{2}$
• D

  $4$

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