Which cloud service model removes the need for employees to install, manage, or update infrequently used software?

Software-as-a-Service (SaaS) is the correct answer because it delivers applications over the internet, on demand, and typically on a subscription basis. This model means the cloud provider manages all aspects of the software, including installation, maintenance, updates, and underlying infrastructure, freeing users from these tasks. This is ideal for infrequently used software as it eliminates the overhead of local management. Infrastructure-as-a-Service (IaaS) provides virtualized computing resources over the internet, but users are responsible for installing and managing operating systems, applications, and data. Platform-as-a-Service (PaaS) offers a development and deployment environment, where users manage their applications and data, but the provider manages the underlying infrastructure and operating system. "Business process as a service" is not a standard cloud service model.