A beam of light is sent along the line $\mathrm{x}-\mathrm{y}=1$, which after refracting from the x-axis enters the opposite side by turning through ${30}^0$ towards the normal at the point of incidence on the x-axis. Then the equation of the refracted ray is 

• A

  $\left(2-\sqrt{3}\right)\mathrm{x}-\mathrm{y}=2+\sqrt{3}$

• B

  $\left(2+\sqrt{3}\right)\mathrm{x}-\mathrm{y}=2+\sqrt{3}$

• C

  $\left(2-\sqrt{3}\right)\mathrm{x}+\mathrm{y}=(2+\sqrt{3})$

• D

  $\mathrm{y}=\left(2-\sqrt{3}\right)\left(\mathrm{x}-1\right)$