Please help:)

important

I beleive its the middle/second option :)

Explanation:

Sorry if I'm wrong but Newton's third law is "for every action (force) in nature there is an equal and opposite reaction." meaning if object A exerts a force on object B, then object B also exerts an equal and opposite force on object A so I beleive the moon would push up on the astronaut with a force of 300 N

I hope this helps, have a good day :)