Assume the following: 1. An organizational unit has 2 database servers, 2 application servers, and 15 clients.
2. Database server performs data storage and data access logic.
3. Application server performs business (or application) logic.
4. One database server and one application server are used to address any client's request.

Question: Such a client-server architecture would be typically classified as:

a. 4-tier architecture (because there are four servers in this network).
b. 5-tier architecture (because there are four servers and one client in the network).
c. 3-tier architecture (because the database server, the application server, and the client each represent one tier respectively).
d. n-tier architecture, where n=19 (because there are 19 computers in the network).