A string is wrapped around a disk of mass M and radius R. Starting from rest, you pull the string with a constant force F along a frictionless surface. At the instant when the center of mass has moved a distance d, a length L of string has unwound off the disk. How much rotational kinetic energy does the disk have in the final state? A. Fd F B. FL C. F(L + d) L+d Initial: D. O d E. F(L - d) F F. FLd Final: top view