I talked around this question. Not on purpose...I was just in a hurry and ended up misinterpreting it as something along the lines of, "what do you need your startup to be doing in three months", or something (I dunno what I was thinking...but my answer kinda makes sense in that context). We got to the interview, anyway.

So, I don't think any one question is going to kill your chances. Show that you know how to think about the value of your business idea, that you have the capacity to build your idea, and that you are willing to build it. Everything else is gravy. I suspect clear and concise sentences go very far, as well.