Interviewer: How do you handle a situation when one of your clients doesn't understand what you've been telling him, and keeps asking you for help?

Interviewee: Well, I try to avoid getting snotty, and will look for a way to re-word what I've been telling him in a way that's simpler.

Seems perfectly acceptable to me, but then, I haven't gone to any job interviews that require dressing up more than clean jeans and a sweater.