The correct answer is: B. 3-tier
A 3-tier system is a client-server architecture that divides an application into three logical and physical computing tiers: the presentation tier, the application tier, and the data tier.
The presentation tier is responsible for the user interface. It receives input from the user and sends it to the application tier.
The application tier is responsible for processing the user input and returning the results to the presentation tier.
The data tier is responsible for storing and retrieving data.
A 3-tier system is more scalable and reliable than a 2-tier system because the application logic is separated from the data storage. This makes it easier to add new features and to improve performance.
A 4-tier system is a client-server architecture that divides an application into four logical and physical computing tiers: the presentation tier, the application tier, the data tier, and the infrastructure tier.
The infrastructure tier is responsible for providing the underlying infrastructure for the application, such as the operating system, the database, and the network.
A 4-tier system is more complex than a 3-tier system, but it can be more scalable and reliable.
An n-tier system is a client-server architecture that divides an application into n logical and physical computing tiers. The number of tiers can vary depending on the specific needs of the application.
An n-tier system is the most flexible type of client-server architecture, but it can also be the most complex.