A body of 5kg weight kept on a rough inclined plane of angle $30^{\large\circ}$ starts sliding with a constant velocity.Then the coefficient of friction is (assume $g=10m/s^2$)

Question

$\begin{array}{1 1}\large\frac{1}{\sqrt 3}\\\large\frac{2}{\sqrt 3}\\\sqrt 3\\2\sqrt 3\end{array}$