$\lim _{x \rightarrow 0} \frac{(\sqrt{2})-\sqrt{1+\cos x}}{\sqrt{15+\cos 2 x}-4}=$

• Correct answer
  A

  $-\frac{1}{\sqrt{2}}$
• B

  $\frac{1}{\sqrt{2}}$
• C

  $\sqrt{2}$
• D

  $-\sqrt{2}$

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