What plan do the king and polonius devise to test whether or not this cause of hamlets conduct is love for ophelia?

To test whether Hamlet's strange behavior is caused by his love for Ophelia, the king and Polonius decide to arrange a meeting between Hamlet and Ophelia in the queen's closet, where they will eavesdrop on their conversation. They believe that if Hamlet truly loves Ophelia, he will express his feelings during this encounter. This plan aims to confirm or disprove the theory that Hamlet's madness is rooted in his unrequited love for Ophelia.