If you need to update data in the main workflow based on the processed data from the invoked workflow, which argument type should be used?

Using an In/Out argument in this scenario is appropriate because it allows for both receiving and updating data between the main workflow and the invoked workflow. This argument type enables you to pass data into the invoked workflow while also allowing that workflow to modify the data and send it back to the main workflow.

In the context of your requirement to update the main workflow's data based on what’s processed in the invoked workflow, the In/Out argument serves the dual purpose effectively. When the invoked workflow is executed, it can access existing data (as an 'In' parameter), process it accordingly, and return the modified data back to the main workflow (as an 'Out' parameter). This two-way communication ensures that both workflows are working with the most up-to-date information.

In contrast, using an In argument would only allow sending data into the invoked workflow, without the capability to return the modified data. An Out argument would enable you to retrieve the data after it has been processed, but it wouldn't allow you to send initial data into the invoked workflow. A static variable would not work for this scenario, as static variables maintain a single instance across multiple invocations and do not facilitate the required data exchange effectively.