Alonso, an Event Planner for a Conference Center, Receives an Email

Alonso, an event planner for a conference center, receives an email from a potential customer who wants to book the conference center's largest space to host a real estate seminar. Since the space is booked on the date specified by the customer, Alonso needs to turn down the customer's request. Which of the following delivers this message in the most positive manner?

A) This is in reply to your request for one of our conference rooms. I regret to inform you that our largest conference room is booked for your specified date. Would you be interested in booking a space for a different date?
B) I have received your request for our largest conference room. As this is the peak exhibition season, we cannot comply with your request as the room is booked for the date specified. We sincerely hope to be contacted at a later time.
C) I am sorry to inform you that the largest room at the conference center is booked. I have instead sent you a list of the other rooms that are available.
D) Thank you for choosing us. I'm sorry to inform you that the largest conference room is unavailable for the date that you have mentioned. You can still choose from several other dates.
E) Although our largest conference center is booked for the specified date, some slightly smaller spaces are still available. I have attached a document with the specifications and price listings for those rooms.