A particle is thrown at time t = 0 with a velocity of 10 ms^-1 at an angle 60^o with the horizontal from a point on an inclined plane, making an angle of 30^owith the
horizontal. The time when the velocity of the projectile becomes parallel to the incline is

• A

  $\frac{2}{\sqrt{3}}\mathrm{s}$

• B

  $\frac{1}{\sqrt{3}}\mathrm{s}$

• C

  $\sqrt{3}\mathrm{s}$

• D

  $\frac{1}{2\sqrt{3}}\mathrm{s}$