Which of the following browser capabilities can be accessed through Local Actions?

Local Actions in Salesforce refer to client-side capabilities, which allows for the creation of interactive user experiences directly within the user's browser. One of the primary functionalities of Local Actions is to enhance user interface interaction by providing feedback or notifications in response to user actions.

Displaying pop-up alerts is a capability accessible through Local Actions because it directly interacts with the user's browser environment. By utilizing local resources, users can receive immediate notifications, confirmations, or alerts—ensuring they are informed of certain actions or statuses without needing to interact with server-side processes.

The other options pertain to functionalities that require server interaction or backend capabilities. Opening database connections, modifying server configurations, and executing server-side scripts all involve operations that occur on the server rather than within the client's browser. These actions cannot be performed through Local Actions since they do not operate within the context of client-side scripting and would require secure server access and execution environments.