take component of velocities along rod and equate them
Opt C and D kese kare?
For D take height of point B as y then find com in terms of y and then differentiate and substitute dy/dt=4
And bro for C just vector sum of the end points may give you the ans
Ignore this#5 bro .. now i got it you can do C by using IAOR
I hope you have understood, If you want detailed solution be free to ask