Definition: In this task you are given a story and a question regarding that story. You must judge whether the question is answerable based on the info given to you. Label the instances as "Answerable" or "Not Answerable" based on your judgment. the story and the question are separated by a new line character.
Input: Lucy was in her grandpa's den. There was a bookshelf full of encyclopedias. She picked up the letter B book. Her and her grandma sat and flipped through the birds. When grandpa saw them he wasn't upset Lucy had been in his den.
Why was Lucy in her grandpa 's den?

Answerable