Two Identical Disks, with Rotational Inertia I (= 1/2 MR²)

Multiple Choice

Two identical disks, with rotational inertia I (= 1/2 MR²) , roll without slipping across a horizontal floor and then up inclines.Disk A rolls up its incline without sliding.On the other hand, disk B rolls up a frictionless incline.Otherwise the inclines are identical.Disk A reaches a height 12 cm above the floor before rolling down again.Disk B reaches a height above the floor of:

A) 24 cm
B) 18 cm
C) 12 cm
D) 8 cm
E) 6 cm