A disk with a radius of 0.5m is free to rotate around its center without friction. A string wrapped around the disk is pulled at an angle of 30 degrees from a tangent line, as shown above, exerting a force F at an angle on the edge of the disk for 1 s. What is the torque acting on the disk at the moment pictured?
A. 0.5F
B. 0.5Fsin30
C. 0.5Fcos30
D. It cannot be determined without knowing the rotational inertia of the disk.