The correct answer is B. Tivoli.
Tivoli is a software platform that provides a wide range of IT management capabilities, including monitoring, provisioning, and configuration management. It is used by businesses of all sizes to manage their IT infrastructure and applications.
WebSphere is an application server platform that provides a runtime environment for Java applications. It is used by businesses to develop and deploy Java applications.
Nebula is a cloud computing platform that provides a set of services for managing and deploying cloud applications. It is used by businesses to build and manage their own private clouds.
Altix is a high-performance computing platform that is used by businesses and research institutions to perform complex calculations.
Tivoli is the correct answer because it is a software platform that provides monitoring, provisioning, and configuration management capabilities. These capabilities are necessary for managing virtual cluster operations.