Answer:
1. First of all, Ophelia rejects Hamlet - This is the part Hamlet becomes angry and tells her he had never loved her, and that she should become a nun.
2. The play within a play - Hamlet made the actors act the events from his real life so as to see if Claudius would reveal his guilt.
3. Claudius' attempted prayer - Claudius understands that he had done wrong and he regrets doing it, however, it is too late for him to take it back.
4. Polonius is killed - Polonius was hiding behind a curtain, and Hamlet thought it was Claudius, he killed him.
Step-by-step explanation: