Final answer:
Using a cloud service to host DNS & DHCP servers exemplifies Infrastructure as a Service (IaaS), offering flexibility and control over online virtualized computing resources.
Step-by-step explanation:
When a company uses a cloud service to host DNS & DHCP servers, this is an example of Infrastructure as a Service, or IaaS. This type of cloud environment provides virtualized computing resources over the internet. IaaS gives clients the highest level of flexibility and management control over their infrastructure compared to PaaS and SaaS. As such, IaaS provides businesses with the ability to manage servers, storage, and other infrastructure elements without having to purchase or maintain their own hardware.