What is $\int\left(\frac{1}{\cos ^2 x}-\frac{1}{\sin ^2 x}\right) d x$ equal to?

• Correct answer
  A

  $2 \operatorname{cosec} 2 x+c$
• B

  $-2 \cot 2 x+c$
• C

  $2 \sec 2 x+c$
• D

  $-2 \tan 2 x+c$ where $c$ is the constant of integration.

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