The correct answer is A: The freshness check can be disabled with freshness: null.
In dbt, freshness checks are controlled by the freshness configuration block within a source definition. If a project includes a default freshness configuration, but you want to turn off freshness checking for a specific table, you can explicitly set freshness: null. This overrides inherited settings and tells dbt not to compute or evaluate freshness for that object.
Option B is incorrect because dbt evaluates all configured sources before finishing; it does not exit after the first failure. Instead, it completes the run and reports pass/warn/error statuses according to the configured thresholds.
Option C is incorrect because the placement of freshness checks is flexible. Some teams run dbt source freshness first to validate data arrival before running models; others run it separately or at the end of a workflow. There is no requirement that it always be last.
Option D is incorrect because dbt build does not automatically run freshness checks. Freshness checks are performed only when dbt source freshness is executed explicitly or configured in a dbt Cloud job step.
Therefore, A is the only statement that correctly describes the behavior of source freshness checks.