Definition: In this task, you will be given a short story. One sentence from the story is chosen. Consider the events that happen before that sentence, or are likely to have happened before it. Does any of them directly cause it, or simply make it possible? You should write your answer in the form " A >causes/enables> B". Try to use phrases and sentences from the story to compose your answer when possible.
Input: story: Trevor and his wife were at home on his day off. They decided to spend their day watching a movie together. Right as they sat down to start the movie, they heard a doorbell. Trevor got the door and saw his parents had come to visit. They all sat and watched the movie together on the couch.
 selected sentence: Trevor got the door and saw his parents had come to visit.

Trevor hears a doorbell >Causes/Enables> Trevor answers the door