When pushing off the wall doing breaststroke, swimmers must do a/an pull?

i started swimming this year its pretty fun : ) I believe the answer to your question would be a pull down/breakstroke pull

Explanation:

I hope this helps your welcome..

Pull-downs are essential to a fast breaststroke race. Without a good pull-down, you have a major disadvantage. You don’t want to start the race behind your opponents! If you’re looking to improve your breaststroke time, mastering the pull-down is a great way to do it. This guide is filled with easy steps to strengthen your race through a powerful pull-down.

it's c. (to reduce the greenhouse effect/carbon gasses)