How should you complete the relevant Windows PowerShell script?

HOTSPOT
You are the Microsoft Exchange Online administrator for your company. The company has been using Exchange Online for over two years.
Employees report that items are disappearing from their primary mailboxes. You discover that an old retention policy is enabled for the employee mailboxes.
You need to ensure that items are not automatically removed from employees’ primary mailboxes.
How should you complete the relevant Windows PowerShell script? To answer, select the correct code segment from each list in the answer area.
Hot Area:

Correct Answer:

Explanation/Reference:
Explanation:
We need to remove any retention policies from the mailboxes.
Box 1: Use the Get-Mailbox cmdlet to retrieve a list of all mailboxes.
Box 2: The -Filter {(RecipientTypeDetails -eq ‘UserMailbox’)} option is used to filter the list of mailboxes to a list of user mailboxes only (thus excluding Room mailboxes, Resource mailboxes etc).
Box 3: We use the Set-Mailbox cmdlet with the -RetentionPolicy parameter to assign retention policies to mailboxes (in this case, all the user mailboxes retrieved by the command in box 1 and box 2.
Box 4: A RetentionPolicy value of $null removes any retention policies assigned to the mailboxes.
References: http://o365info.com/manage-retention-policy-by-using/