You are the IT administrator of an organization with a Microsoft 365 subscription and Microsoft 365 E5 licenses assigned to your users. You have been tasked with removing all access to company resources for a user in the legal department, and eventually delete the user. However, the user’s mailbox content must be retained indefinitely. The solution should be cost effective. What should you do?

Answer options:

A.Disable the user In Microsoft 365 Admin Center but do not remove the Microsoft 365 E5 license.
B.Delete the user in Microsoft 365 Admin Center. The mailbox content will be preserved until manually purged.
C.Export the user from the Microsoft 365 Admin Center. The Export will contain all mailbox items. Save the content on an external drive and store it in a secure location. 
D.Place the mailbox on Litigation Hold

Correct Answer: D 
When you place a mailbox on litigation hold, the content is preserved for a specified duration or until you remove the hold. By placing the mailbox of the user in the legal department on litigation hold, the mailbox content is saved as requested. 
Note: Placing a mailbox on hold Litigation hold will also place the user`s archive mailbox on hold - if present. 
See exhibit: 

Option A is incorrect. Keeping the user in a licensed mode will retain the mailbox, but license costs will occur. This will also prevent you from deleting the user. 
Option B is incorrect. This is incorrect. The employee`s mailbox data is retained for 30 days after the account is removed. During this period, you can still recover the mailbox data by undeleting the account. After 30 days, the data is permanently removed.
Option C is incorrect. This is incorrect. The Export Users function in Microsoft 365 Admin Center will not export mailbox content. 
Reference:
To know more about alert inactive mailboxes, please refer to the link below: 

https://docs.microsoft.com/en-us/microsoft-365/compliance/inactive-mailboxes-in-office-365?view=o365-worldwide