Task: Question Answering
Input (English): Passage: The mail delivery in my neighborhood comes at 10 in the morning . It was already noon , so I decided to check the mail . I grabbed my mailbox key and walked down to the mailbox at the end of my driveway . There was a letter inside the mailbox . I took it out of the box and read the front . It was addressed to me , so I closed the mailbox door and locked it . I read the letter and saw that it was addressed from my Aunt Karen . I went to the kitchen and grabbed a letter opener from my utensil drawer . I opened up the envelope with the letter opener , and took out a piece of paper . My Aunt Karen wrote me a letter to tell me that she was coming to visit my area and would love to stop by for dinner . Question: When did the box get unlocked? Option1: Upon seeing a letter inside. Option2: When the letter was written.
Output (English): Upon seeing a letter inside.