What should you identify?

You have an Exchange Server 2013 organization.
A user named User1 has a mailbox that is enabled for Unified Messaging (UM). User1 has nine call
answering rules.
When User1 attempts to create a new call answering rule, the user receives an error message.
You need to identify what prevents User1 from creating a call answering rule.
What should you identify?

A.
The mailbox of User1 has the CallAnsweringRulesEnabled parameter set to $false

B.
The UM mailbox policy of User1 has the AllowCallAnsweringRules parameter set to $false.

C.
User1 exceeds the Inbox rules storage quota.

D.
User1 has the maximum number of call answering rules allowed.

Explanation:
A total of nine call answering rules can be set up for each UM-enabled mailbox.