Which tool should be used to import files that arrive at varying times from a data warehouse?

The tool suitable for importing files that arrive at varying times from a data warehouse is the File Drop Automation feature within Automation Studio. This option is designed specifically for scenarios where files are expected to be placed in a designated folder, allowing the automation to trigger whenever a new file is detected.

With File Drop Automation, marketers can set up an automation that executes when a file appears in a specified location, facilitating timely and efficient data handling without needing a strict schedule. This is particularly beneficial for files that may not arrive at consistent intervals, as it optimizes the import process based on actual file arrivals rather than pre-defined times.

In contrast, other options, such as Scheduled Automation, are based on fixed schedules and would not adapt smoothly to varying file arrival times. Contact Builder Import Automation focuses more on importing data directly into Contact Builder environments rather than responding to file events, and Journey Builder Contact Automation is aimed primarily at managing contacts within customer journeys rather than direct file importation. Hence, File Drop Automation stands out as the most appropriate choice for the specified scenario.