A is correct because the Service Cloud Connector only works with registered B2C Commerce customer accounts and does not support guests or anonymous storefront shoppers. The connector uses the customer ID to link the Service Cloud contact with the B2C Commerce customer profile.
B is incorrect because the Service Cloud Connector supports both SOAP and REST services for data synchronization between Service Cloud and B2C Commerce.
C is incorrect because the Service Cloud Connector requires B2C Commerce to be registered as a remote site in Service Cloud regardless of the geographic region. This is to allow outbound messages from Service Cloud to B2C Commerce.
D is incorrect because the Service Cloud Connector requires a dedicated Integration User with administrative rights in both Service Cloud and B2C Commerce. This user is used to authenticate and authorize the data synchronization between the two systems.
Reference:
1: https://documentation.b2c.commercecloud.salesforce.com/DOC1/topic/com.demandware.dochelp/ServiceCloud/ServiceCloudConnectorOverview.html
2: https://documentation.b2c.commercecloud.salesforce.com/DOC1/topic/com.demandware.dochelp/ServiceCloud/ServiceCloudConnectorDataSynchronization.html
3: https://documentation.b2c.commercecloud.salesforce.com/DOC1/topic/com.demandware.dochelp/ServiceCloud/ServiceCloudConnectorSetup.html
4: https://documentation.b2c.commercecloud.salesforce.com/DOC1/topic/com.demandware.dochelp/ServiceCloud/ServiceCloudConnectorUserSetup.html