As shown in the figure , auniform disc of mass m is rolling without slipping with an angular velocity w. The portion AB is rough and BC is smooth. When it crosses the point B disc will be in

Question

 

$\begin{array}{1 1} a) \text{translational motion only} \\ \text{ b) pure rolling motion} \\ \text{c) rotational motion only} \\ \text{d) none of these} \end{array}$