You have an Exchange organization.All servers in the organization have Exchange Server 2010 Service Pack 1 （SP1） installed. You need to ensure that each user who sends a meeting request to a room mailbox receives a custom message from the mailbox. What should you do from the properties of the mailbox？（）
- AConfigure the Mailbox Features settings.
- BConfigure the Mail Flow settings.
- CEnable the Resource Booking Attendant.
- DConfigure the Resource Information settings.
- EConfigure the Resource In-Policy Requests settings.
- FConfigure the Resource Policy settings.