Answer:
Step-by-step explanation:
This is definitely a rising action. We along with Hamlet always wonder how Claudius is going to respond. I don't care how many times you see Hamlet, you always wonder what Claudius will do. Actors who play Claudius always have their creative juices flowing when the scene comes up.
I think Hamlet starts singing afterward. He's sure. There's no doubt in his mind what will happen or at least how he will take action.