A roller is made by joining together two cones at their vertices O, ti is kept on two rails AB and CD, which are placed asymmetrically with its axis perpendiuclar to CD and its center O at the centre of line joining AB and Cd it is given a light push so that it starts rolling with its centre O moving parallel to CD in the direction shown As it moves, the roller wil tand to:
A. turn right
B. go straight
C. turn left and right alternately
D. turn left
