Please help

Which of the following is an example of understatement?
Select one:

When Mike found out he had failed the quiz he said, "Great! All that studying really paid off!"

The girl exclaimed, "If I don't get to school on time, my mom's going to kill me!"

As the man watched the tornado approaching, he remarked, "Looks like there's going to be a breeze today."

As she watched the love of her life walk away. Michelle shouted, "You're breaking my heart!"