Unity Catalog in Databricks provides the ability to attach tags (key-value metadata pairs) to securable objects such as catalogs, schemas, tables, volumes, and functions. Tags are critical for governance, compliance, and automation, as they allow organizations to track metadata like sensitivity, ownership, business purpose, and retention policies directly at the object level.

According to the official Databricks SQL reference for Unity Catalog, the correct way to programmatically add tags to a table is by using the ALTER TABLE … SET TAGS command. The syntax is:

ALTER TABLE table_name SET TAGS ( ' tag_name ' = ' tag_value ' , ...);

This command can be used within ETL workflows or jobs to automatically apply metadata during or after ingestion, ensuring that governance and compliance rules are embedded in the pipeline itself.

Option A is correct because it uses the supported syntax for applying tags.

Option B (APPLY TAGS) is not valid SQL in Unity Catalog and is not recognized by Databricks.

Option C confuses COMMENT with TAGS. While COMMENT can add descriptive text to a table, it does not handle tags.

Option D (SET TAGS FOR) is not a valid SQL construct in Databricks for applying tags.

Thus, Option A is the only valid and documented way to programmatically set tags on a table in Unity Catalog.