Managing CI classes and Principal Class designation is a schema-level CMDB activity that directly impacts how CIs appear in ITSM processes such as Incident, Change, and Problem. In ServiceNow, these activities require specific administrative privileges to ensure governance, security, and upgrade safety.

The sn_cmdb_admin role is required because it provides administrative access to CMDB structures, including CI class hierarchy management, Principal Class configuration, and overall CMDB governance. Without this role, users cannot add, remove, or govern CI classes effectively.

The personalize_dictionary role is also required because adding or removing CI classes involves dictionary-level changes. CI classes are implemented as tables that extend the CMDB schema, and modifying the Principal Class filter relies on dictionary metadata. This role grants permission to create, modify, or remove class definitions safely.

The sn_csdm_admin role focuses on managing CSDM constructs (domains, services, lifecycle alignment) but does not grant dictionary or schema modification rights. The cmdb_query_builder role is used only for querying and reporting and does not allow structural changes.

Therefore, the two required roles are personalize.dictionary and sn_cmdb_admin, making Options A and B correct.