In this task, you will be given a short story. One sentence from the story is chosen. Consider the events that happen after that sentence. Is any of them directly caused by it, or is made possible by it? 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. Do not change the main selected sentence in your answer.

story: Emma was working on her math homework. She asked her dad to help her. Her dad didn't understand the problem. Emma called her classmate. Emma's classmate explained the problem.
 selected sentence: Her dad didn't understand the problem.
Her dad doesn't understand the problem >Causes/Enables> Emma calls her classmate