Explanation/Reference:
Explanation:
For distribution groups stored in an organization's address book, the group is counted as one recipient.
Incorrect Answers:
B: The Set-TransportConfig cmdlet is usedto modify the transport configuration settings for the whole Exchange organization, not for a single user.
C: A throttlingPolicy does not refer to the number of recipients of email messages.
References: https://technet.microsoft.com/en-us/library/exchange-online-limits.aspx#RecipientLimits