Also, @Jenna143 it's important to distinguish between booking requests and inquiries.
Booking requests MUST be either accepted or declined. A simple reply to an inquiry counts as a response and stops the clock ticking down (i.e. is counted in your stats). Even though there are preapprove/accept/decline buttons, you don't have to choose one. Confusing, I know, but if the guest just wants to ask a simple question, they have to pick calendar dates.
After your reply, the guest's inquiry will show on your dashboard. You can just dismiss it, if you've dealt with the question.