The correct answer is C. Virtualization.
Virtualization is the process of creating a virtual version of something, such as a computer, server, operating system, or storage device. It allows multiple operating systems to run on a single physical computer, and it can be used to create isolated environments for testing or development.
Pooling and sharing of resources is a key concept in cloud computing. It allows multiple users to access and share resources, such as servers, storage, and networking, on an as-needed basis. This can help to reduce costs and improve efficiency.
Polymorphism is a programming concept that allows objects to have multiple forms. It is often used to create code that is more flexible and reusable.
Abstraction is a programming concept that hides the details of implementation from the user. It allows users to focus on the essential aspects of a program without having to worry about how it is implemented.
None of the other options are directly related to pooling and sharing of resources.