The best Salesforce Shield capabilities for the customer are to restrict access to SF from users outside specific geography, implement transaction security policies to prevent export of SF data, and encrypt sensitive customer information maintained in SF. Salesforce Shield is a set of security features that help protect enterprise data on the Salesforce platform. It includes three components: Event Monitoring, Platform Encryption, and Field Audit Trail. Restricting access to SF from users outside specific geography can be done using network-based security features, such as IP whitelisting or VPN. Transaction security policies can be used to define actions or notifications based on user behavior patterns, such as exporting data or logging in from an unknown device. Platform Encryption can be used to encrypt data at rest using a tenant secret key that is controlled by the customer.

Implicit sharing will automatically handle this sharing requirement with standard functionality, as it grants read-only access to parent accounts when users have access to child opportunities. This is also known as account-opportunity sharing3. Creating a criteria-based sharing rule (option A) or an owner-based sharing rule (option D) is not necessary, as they are used to grant additional access based on record criteria or ownership. Adding appropriate users to the account team (option C) is also not required, as it is used to grant access to specific users or groups for individual accounts.

According to this article, person accounts are designed to store information about individual people by combining certain account and contact fields into a single record. This is suitable for a large B2C retailer that needs to model the consumer account structure in Salesforce.