The angle between the straight lines represented by $\left(x^2+y^2\right) \sin ^2 \alpha=(x \cos \alpha-y \sin \alpha)^2$ is

• A

  $\frac{\alpha}{2}$
• B

  $\alpha$
• Correct answer
  C

  $2\alpha$
• D

  $\frac{\pi}{2}$

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