It turns out we all have areas that need improvement or as my friend Denice calls them, "development opportunities". Trust me, I was as shocked as you are to discover this but now that I've come to grips with the fact that I'm not perfect I want to help you answer this question too.
This question is really just an expanded version of "Describe your weaknesses." This question is a great opportunity to speak to areas that you are working on. Just like discussing your weaknesses, this is not the time to talk about your worst traits but rather to talk about the areas your improving. Think back to your reviews and remember what you
Perhaps you are a poor delegator and try to take to much on yourself.