Please see attachment.
Case b: the disk rolls without slipping on the horizontal surface with angular velocity Ω.
Assume pin A is at the edge of the disk.© BrainMass Inc. brainmass.com September 19, 2018, 8:48 am ad1c9bdddf - https://brainmass.com/physics/rotation/angular-velocity-link-bc-170596
It finds the angular velocity of link BC for the instant indciated given two cases. The solution is detailed and was rated '5/5' by the student who originally posted the questions.