When have you displayed a great deal of responsibility?

"Over the summer, I work as a program assistant at a summer camp. Last summer, I was tasked with planning the entire field day, where all different camps come together and compete in various field day events and activities. I had to plan and arrange everything from transportation, to food, to activities and equipment, to first aid, to the schedule, and come up with a separate plan for inclement weather. It was such a huge responsibility, but my manager saw the potential in me and knew, with my attention to detail, that I could pull it off. The day went off without a hitch and I had every single detail planned out. I was so proud of myself and my boss was impressed by all of my work and poise that day."