Determine the kinetic energy of the $20$ $kg$ disk (radius of gyration, $k_g = 0.5$ $m$) at the instant shown. Note that the shown velocity vector refers to the translation of the centre of the wheel. Assume high friction between the disk and the ramp.

A. $\frac {1} {2} (20)(3)^2$
B. $\frac {1} {2} (20)(0.5)^2(10)^2$
C. Answer A + Answer B
D. None of the above