Which cmdlet should you run?

Your Exchange Server 2007 environment has a Mailbox server named Server1. You need to disable subject logging on Server1. You need to be able to continue to use message tracking. Which cmdlet should you run?

A.
Set-MailboxServer Server1 -MessageTrackingLogEnabled $true

B.
Set-MailboxServer Server1 -MessageTrackingLogEnabled $false

C.
Set-MailboxServer Server1 -MessageTrackingLogSubjectLoggingEnabled $true

D.
Set-MailboxServer Server1 -MessageTrackingLogSubjectLoggingEnabled $false