Which screen action provides access to both screen inputs and local variables?

The screen action that provides access to both screen inputs and local variables is the Preparation action. This action is executed when the screen is initialized and plays a crucial role in setting up the data necessary for the screen's user interface.

During the Preparation, you have access to screen inputs, which are values that can be passed to the screen when it is opened. This might include parameters from URLs or parent screens. Additionally, local variables defined within the context of the screen can also be utilized to hold temporary data that is required during the screen's lifecycle. This combines both types of data—inputs and local state—making the Preparation action essential for the setup of the screen.

Other options like Web Services, SQL, and Aggregate are specialized actions that serve different purposes. For instance, Web Services are used primarily to call external APIs, SQL is specifically for database operations, and Aggregate is a way to easily retrieve and manipulate data from the database. However, none of these actions manages screen-level inputs and local variables simultaneously, which is why they are not suitable choices for this scenario.