You need to convert a user mailbox to a resource mailbox

You have an Exchange Server 2007 environment. You need to convert a user mailbox to a resource mailbox. What should you do?

A.
Run the Set-Mailbox cmdlet. Configure the Type value to be Regular

B.
Run the Set-Mailbox cmdlet. Configure the Type value to be Room

C.
Run the Set-ResourceConfig cmdlet. Configure the Instance parameter to be Regular

D.
Run the Set-ResourceConfig cmdlet. Configure the ResourcePropertySchema parameter to be Room