Answer:
D. Decision support systems
Explanation:
Operation Support System, sometimes referred to a group of computer programs that is used by the communications service provider for carrying out various operations or functions, such as monitoring, controlling, analyzing and managing a telephone or computer network.
It is often used by professionals such as Network planners, service designers, operations, architects and engineering teams in the service provider.
There are however, types of Operation Support System which are being used for different and specific purpose. They are classified into the following categories:
1. Transaction Processing Systems
2. Process control system
3. Enterprise collaboration system
4. Enterprise Resource
Hence, from the question above, the DECISION SUPPORT SYSTEM is not classified as Operation Support System.