Which model allows organizations to build cloud infrastructure by using components provided by cloud providers?

The correct answer, which is Infrastructure as a Service (IaaS), is appropriate because IaaS offers users access to computing resources over the internet, including virtual machines, storage, and networks. This model enables organizations to build and manage their cloud infrastructure leveraging the base components provided by cloud providers. With IaaS, users can allocate and provision resources based on their needs, offering flexibility and scalability. For instance, companies can quickly spin up new servers or storage as needed without investing in physical hardware, which can lead to significant cost savings and simplified operations.

The other options represent different service models that serve distinct purposes. Platform as a Service (PaaS) provides a platform allowing developers to build, deploy, and manage applications without worrying about the underlying infrastructure. Software as a Service (SaaS) delivers software applications over the internet on a subscription basis, eliminating the need for installation and maintenance. Database as a Service (DBaaS) focuses specifically on providing database capabilities as a managed service. These models all abstract different levels of underlying infrastructure management, but IaaS is unique in that it gives users the most control and flexibility to build their infrastructure directly from the ground up.