Given a parent and child domain, explain data accessibility between domains.

ServiceNow's domain separation model operates on a hierarchical, top-down principle of data visibility. Users assigned to a parent domain have the ability to view and access data within their own domain as well as all data contained within any of its child domains. This allows a service provider (in the parent domain) to manage and report on all its customers (in child domains). Conversely, users in a child domain are restricted from accessing data in the parent domain or any sibling domains, ensuring data segregation and security for each tenant.

A. Incorrect because data access is not bidirectional. Child domain users cannot access parent domain data by default.
C. Incorrect as this describes bottom-up visibility, which is the opposite of how ServiceNow's domain hierarchy functions.
D. Incorrect because parent domain visibility is recursive; it extends to all descendant domains, including any domains contained within a child domain.

1. ServiceNow Product Documentation: Domain separation explained. "Users in a parent domain can view and access data from its child domains. For example, users in the TOP domain can access data from all other domains... Users in a child domain cannot see data in their parent domain."

2. ServiceNow Product Documentation: Domain hierarchy. "By default, users can see data in their own domain and in child domains. For example, a user in the TOP domain can see records in the TOP domain, the MSP domain, and the Customer A and Customer B domains." This confirms that visibility cascades down the entire hierarchy.