"I plan, organize and prioritize based on the work load and deadlines. I often have multiple projects happening at once so my expertise in doing these things well determines my success."

The interviewer is wanting to hear how you are going to cope with different tasks and deadlines and whether they can be performed without major supervision. The best way to start to plan and prioritize your work is to write down your thought processes, outlining the most urgent tasks and when they should be done in the time-scales provided. Show to the interviewer that you can multi-task, be aware of the urgency levels and meet performance exacting standards and be prepared to talk about all your coping mechanisms.