In a three-tier client-server system, which tier handles the business processing (business logic)?

Answer: B. Function tier (application tier)

A three-tier client-server system divides processing into the presentation tier, which handles interaction with the user (accepting input and displaying results), the function tier, which handles the business processing, and the data tier, which handles access to the database. Because business rules and calculations are gathered in the function tier, changing the screens or the database has less effect on the business processing. Also, only the presentation tier needs to be on the client side, which makes it easy to use a web browser as the terminal.

• A. This tier handles interaction with the user, such as accepting input and displaying results.
• B. Correct. This tier handles the business logic, such as business rules and calculations.
• C. This tier handles searching and updating data in the database.