If $y=\left(x+\sqrt{1+x^2}\right)^n$, then $\left(1+x^2\right) \frac{d^2 y}{d x^2}+x \frac{d y}{d x}$ is

• Correct answer
  A

  $\mathrm{n}^2 \mathrm{y}$
• B

  $-n^2 y$
• C

  $-y$
• D

  $2 x^2 y$

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