Almost everyone has been in this situation. If you say no, intervieweres will usually dig deeper until you can give then an answer. The key is to show how you reacted to the conflict and what you did to resolve it.

I think that everyone at some point has had a conflict at work whether it's with a supervisor or co-worker. I've found that when I'm in a difficult situation, it helps to communicate with the other person, understand their perspective and try to work out a collaborative solution whenever possible.