正解:D
Scalability is the ability of a system to handle increasing or decreasing demand by adding or removing resources accordingly. According to the web search results, scalability is one of the main benefits of using containers in a cloud environment, as containers are lightweight, portable, and independent units of software that can run on any compatible host . A containerized cluster is a group of hosts that run multiple containers and share resources and services. A containerized cluster can scale up or down easily by adding or removing hosts or containers as needed, without affecting the functionality or performance of the applications .