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: Paul took his son to school. But he forgot to give him a lunch. So his son shared food with his friend. But the food made him sick. And Paul never let his son eat school food again.
 selected sentence: So his son shared food with his friend.

Paul forgets to give his son his lunch >Causes/Enables> His son shares food with his friend