Respuesta :
Simply that Hamlet believes that Ophelia had a part to play in the murder of his father.
Answer and Explanation:
Hamlet is aware that he is being watched and that Ophelia is being used to spy on him. His father Polonius and Claudius have ordered Ophelia to spy Hamlet's behaviour. When he discovers that he is being watched by her, he mistreats her and speaks rudely to her. This makes her feel he is mad.