With the Organization-Wide Default (OWD) for Accounts set to Private, access to records not owned by a user must be explicitly granted. A criteria-based sharing rule is the appropriate mechanism to grant access to a specific subset of records based on their field values. In this scenario, a rule can be configured using the IsPersonAccount field (IsPersonAccount = TRUE) to identify all retail customers. This rule would then share these specific Account records with users in the "Retail Sales" role, fulfilling the requirement to grant them access to all Person Accounts while excluding Business Accounts. The "2" in the option is likely a typo; a single rule is sufficient.

B. Create an owner-based sharing rule on AccountContactRelation...

This is incorrect because it shares records from the AccountContactRelation junction object, not the Account object itself, and thus would not grant visibility to the required Account records.

C. Update the Retail Sales profile to grant access to Person Account record type.

This is incorrect because record type access on a profile controls a user's ability to create records of that type and which page layout to use; it does not grant visibility to existing records they do not own.

1. Salesforce Help, "Criteria-Based Sharing Rules": "Criteria-based sharing rules determine who to share records with based on field values... For example, you can create a rule that shares all open cases with a high priority with a specific public group." This directly supports using criteria (e.g., IsPersonAccount = TRUE) to share records.

2. Salesforce Object Reference Guide, "Account": The guide details the IsPersonAccount field, a read-only Boolean field that is true if the account is a person account. This field is the ideal criterion for the sharing rule.

3. Salesforce Security Guide, "Controlling Access Using the Role Hierarchy": This guide explains the layers of data access. It clarifies that after OWDs, "You can use sharing rules to grant additional access to users." It also implicitly distinguishes this from profile-level settings, which control object and field-level security, not record-level access for records owned by others. (See the "Summary of Data Access" diagram).