Option A is correct because authentication credentials should be stored and managed by Experience Cloud as the system of record for this customer data. Experience Cloud acts as an identity provider (IDP) for commerce, meaning that it verifies the identity of customers who log in to ecommerce sites using their communities credentials. Experience Cloud can also leverage Salesforce Identity features to provide secure and seamless authentication across multiple Salesforce clouds and external systems.
Option B is incorrect because address book should not be stored and managed by Experience Cloud as the system of record for this customer data. Address book is mainly used for ecommerce purposes, such as shipping and billing addresses, and it should be stored and managed by B2C Commerce as the system of record. B2C Commerce can also integrate with Experience Cloud to provide a consistent user experience across ecommerce sites and communities.

This answer is correct because it aligns with the executive team's request to see the benefits and return on investment sooner than three years. A multi-phased approach allows for incremental delivery of functionality across all clouds, which can provide value to the business and customers faster and more frequently. Reference: https://trailhead.salesforce.com/en/content/learn/modules/solution-design/solution-design-process

This answer is correct because managing inventory data inside of B2C Commerce makes it easier to parse by store and enable buy online pick up in store (BOPIS) functionality. B2C Commerce can store inventory information for multiple locations and provide real-time availability information to customers and service agents. B2C Commerce can also integrate with Salesforce OMS to manage order fulfillment and payment processing for BOPIS orders. References: https://help.salesforce.com/s/articleView?id=sf.
b2c_commerce_oms_integration.htm&type=5

This answer is correct because it minimizes the migration of customer profile data by using Salesforce Identity as the primary authentication method. Salesforce Identity can act as an identity provider (IDP) for both B2C Commerce and Experience Cloud, and it can store customer profile data in a single place. This reduces the need to duplicate or sync customer data across multiple systems. References: https://help.
salesforce.com/s/articleView?id=sf.b2c_commerce_service_cloud_integration.htm&type=5

This answer is correct because Salesforce Connect can be used to display external data in Salesforce without copying or storing it. Salesforce Connect uses external objects to access data from an external system via an adapter. This way, the order data from the ERP system can be displayed in Service Cloud as read-only records without consuming additional storage space. Reference: https://help.salesforce.com/s/articleView?id=sf.datacloud_connect.htm&type=5