Say what was the right thing to do.
Imagine your behavior in a situation.
Say what other possibilities there were.
What would you have done? I would have said no politely. I wouldn't have lost my temper.
What else could she have done? She could have told him not to call again. She couldn't have done much else.
What should she have done? She should have said no politely. She shouldn't have yelled at him.
