I think it is C because A is missing commas, B doesn't need them and D doesn't need one.
Answer:
Ophelia, left alone on stage, grieves the loss of Hamlet’s mind and her own misfortune.
Prior to this moment, the king Claudius and Ophelia’s father, Polonius order Ophelia to stop seeing Hamlet as they hide nearby to view his reaction. What follows is one of the most explosive scenes of the play.
Explanation:
I would put a comma before and or leave the comma out
