In scenarios involving a large dataset, such as a database of over 10,000 book titles, the most efficient way to allow users to find and select an item is by using an autocomplete control. This approach enhances user experience by filtering options based on user input, making it easier to navigate through large lists of data.

Why not a drop-down? A drop-down control (Options A and B) would not be practical for such a large number of items because it would require loading all items at once, which can lead to performance issues and a poor user experience.

Why an autocomplete control? The autocomplete control (Option C) is designed for scenarios like this. It allows the user to begin typing the name of a book, and the control suggests matching titles based on the input, narrowing down the options dynamically. This approach is much more user-friendly and efficient for large datasets.

Why sourced from a data page? Sourcing the autocomplete control from a data page (Option C) is the best practice because it allows for the efficient loading and caching of data. Data pages can be configured to refresh at appropriate intervals or under specific conditions, ensuring that the data is up-to-date. Furthermore, using a data page abstracts the data source from the control, making the application easier to maintain and update.

This setup ensures a smooth and efficient user experience, allowing for quick and easy selection from a vast database of book titles