Be honest. Describe a situation (a professional one is ideal, but if you do not have a great deal of work experience, think of a time when you volunteered for a group, helped a friend or sibling move into their apartment, etc.) where you felt stressed, and explain how you were able to manage it.

Stating that you don't work well under pressure/stress. All positions can be stressful at times, and the interviewer wants to know how you handle it, not that you are unable to do so.

"At XX company, I was often required to handle seemingly unlimited requests at one time. I would sometimes get overwhelmed and stressed, but I found that by taking a step back for a minute, evaluating the work closely, and communicating directly with the request owners, I couuld prioritize more effectively."

"When I was a receptionist at XX hospital, we had multiple unexpected patient emergencies. At first it was scary, but after a bit of a learning curve I learned to calmly and effectively handle anything that came my way."