HOTSPOT
Contoso, Ltd., has an Office 365 tenant. All employees have Exchange Online mailboxes. You create a shared mailbox named [email protected].
You need to grant full mailbox access to [email protected] for the SharedMailbox1 mailbox.
How should you complete the relevant Windows PowerShell commands? To answer, select the appropriate
Windows PowerShell commands from each list in the answer area.
Hot Area:
https://technet.microsoft.com/en-us/library/bb124097(v=exchg.160).aspx
Answer: 
Explanation:
The Add-MailboxPermission is available in on-premises Exchange Server 2016 and in the cloud-based service.
Some parameters and settings may be exclusive to one environment or the other.
Use the Add-MailboxPermission cmdlet to add permissions to a mailbox.It applies to Exchange Online and
Exchange Server.
Example:
This example grants Kevin Kelly full access to Terry Adams’s mailbox.Add-MailboxPermission -Identity “Terry Adams” -User KevinKelly -AccessRights FullAccess -InheritanceType
All
References:
shouldn’t this be trustee and not user? or is the previous similar question that uses trustee incorrect?
scratch that the correct syntax can be found in this link:
https://technet.microsoft.com/en-us/library/ff935839(v=exchg.160).aspx
Correct Answer is Add-RecipientPermission, [email protected], -Trustee [email protected]
also answer offered is correct according to the following link:
https://technet.microsoft.com/library/bb124097(EXCHG.80).aspx
in this case which option would you use both do the same thing and both options are available here. therefore this can be considered a double edged sword with no correct answer.