What is the correct syntax for defining a source in dbt using Jinja?

The correct syntax for defining a source in dbt using Jinja is to use the source function, which is specifically designed to reference external sources in your dbt project. The proper way to call this function is by passing the source name and the table name as arguments within the parentheses.

The syntax {{ source(source_name, table_name) }} correctly utilizes the function format, indicating that source_name and table_name should be replaced with the actual names used in your project. This is important for dbt models, as it allows you to reference the correct external tables or views from your source systems.

Using quotes around the table_name in option D would also work, but the unquoted version is typically the most common practice as it allows for more dynamic query construction. The other options do not use the correct function syntax or structure, making them unsuitable for defining a source in dbt. Therefore, the choice that follows the correct syntax and conventions of dbt is indeed the one that relies on the source function with its proper call format.