In ServiceNow, domain separation is used to manage data visibility and access control in a multi-tenant environment1. The 'contains' relationship in domain separation defines a hierarchy where a parent domain contains child domains, and by default, users in a parent domain can see the records in child domains1.
Given that TOP is the parent domain for MSP, ACME, and Initech, and MSP contains TOP, UserA in MSP would already have visibility into TOP. However, for UserA to read records in ACME, additional configuration is required because ACME is not a child domain of MSP by default.
The correct action is to add visibility to ACME for UserA . This is typically done by configuring the user's domain membership or by adjusting the domain visibility settings to include ACME for UserA. This ensures that UserA can access records in ACME while still being primarily associated with the MSP domain1.
The 'contains' relationship between MSP and ACME (A) is not necessary because it would imply a hierarchical relationship that does not reflect the given structure. Adding both visibility to ACME for UserA and contains between MSP and ACME (B) is also not required and could potentially create an incorrect domain hierarchy. No additional configurations (D) would not suffice as it would not grant UserA the access needed to read records in ACME.