Describe the most responsible position you have held and the duties it entailed.

I have a interview for a physical therapy school and I needed help answering a question. The questions states “Describe the most responsible position you have held and the duties it entailed. Have you held a position of responsibility related to a community service activity?”

My answer i have briefed up is when I was in High school, I worked with my history teacher on few community activities and one special event was a collecting food charity to give can foods or any type of food to some parts of our Berea where poor people lived or well a food bank actually. My responsible duty was I would help with either making advertising signs or boards and have them out in the halls or front of our school. I would also keep in check of how much food we gained and would help deliver the food to the food bank

Can someone help me out and answer this question with the experience I showed here? Please provide an example of how I should answer this.

Also, can someone help tell me what kind of position this was I held? 

Thanks 🙂