Master-Detail Relationship Behavior:

In a master-detail relationship, access to child records (Invoice) is determined by access to the parent record (Account).

Since the AR team does not have access to accounts, they cannot see invoices related to those accounts.

Why Option B is Correct:

To resolve this issue, a sharing rule must be created to share accounts with the AR team. This will cascade access to the related Invoice records due to the master-detail relationship.

Why Others Are Incorrect:

Option A: The AR team has object-level access to Invoice but still cannot see the records due to account-level sharing restrictions.

Option C: Sharing rules for invoices are not applicable because access to invoices is governed by account-level access in a master-detail relationship.

For detailed information, refer to Salesforce Sharing and Object Relationships documentation: https://help.salesforce.com/