Which event is ideal for reacting to changes in data?

Choosing the "Render" event as ideal for reacting to changes in data is appropriate because this event is triggered when a screen or a block is about to be presented to the user. It is the right moment to update the UI based on the latest data or state. When the Render event occurs, it allows developers to dynamically modify the visual output before it is displayed, ensuring that users see the most current information following any updates or changes.

In the context of reactive applications, using the Render event means that any changes in data that need to affect what the user sees can be handled effectively at this stage. With this approach, developers can ensure that the interface remains in sync with the underlying data model, providing an optimal user experience.

The other options, while useful in various contexts, do not align as closely with the requirement to react to data changes. The Ready event is typically used for initialization when the application is loaded. The Destroy event is invoked when an element is no longer needed and is being removed, making it unsuitable for reacting to changes. Lastly, the After Fetch event is relevant when data has just been retrieved, but it does not directly handle the presentation of that data, which is critical for reacting to changes visually on the screen.