In Snowflake's object hierarchy, schemas are used to logically group database objects such as tables, views, stages, and user-defined functions. A database can contain one or more schemas, providing a way to organize and manage objects and their security. This structure helps prevent naming conflicts and allows for granular access control.

B. Roles are used for access control and privilege management, not for organizing database objects like tables and views.

C. Tables are database objects themselves; they contain data and are organized within schemas, but they do not organize other objects.

D. Stages are locations (internal or external) for storing data files before loading; they do not group other database objects.

- Snowflake Documentation. (n.d.). Overview of Databases. Retrieved from https://docs.snowflake.com/en/sql-reference/ddl-database.html#overview-of-databases. (See the section "Database Objects" which describes the hierarchy).

- Snowflake Documentation. (n.d.). Understanding Snowflake Table Structures. Retrieved from https://docs.snowflake.com/en/user-guide/tables-intro.html. (See the section "Snowflake Object Hierarchy").