What should you recommend?

You have an Exchange Server 2013 organization that contains a database availability group (DAG)
named DAG1. DAG1 has two members.
You create a mailbox database copy for each database on each DAG member.
You plan to implement a service level agreement (SLA) that meets the following requirements:
All deleted mailboxes must be recoverable for up to six months after they are deleted.
When a mailbox is recovered, the entire contents of the mailbox must be recovered.
You need to recommend a solution that meets the requirements.
What should you recommend?

A.
Get-Mailbox | Set-Mailbox -RetainDeletedItemsFor 180.00:00:00

B.
Get-MailboxDatabase | Set-MailboxDatabase -MailboxRetention 180.00:00:00

C.
Get-MailboxDatabase | Set-MailboxDatabase -DeletedItemRetention 180.00:00:00

D.
Get-Mailbox | Set-Mailbox -Audit Log Age Limit 180.00:00:00