Why would you use the Docker 'run' command?

The Docker 'run' command is specifically designed to create and start a new container from a specified image. When you execute this command, Docker takes the image provided and instantiates it as a running container, which can then execute the commands defined in the image's configuration. This is crucial because containers are isolated environments where applications can run, and the 'run' command is the gateway to deploying these applications based on containerized images.

The 'run' command also has the flexibility to accept configurations for the container's runtime behavior, such as setting environment variables, determining which ports to expose, and mapping volumes for persistent storage. This ability to initiate and configure containers makes the 'run' command central to the Docker workflow for launching applications in isolated environments.

In contrast, the other choices focus on functionalities that are not addressed by the 'run' command. Debugging containers, listing images, or viewing stopped containers requires different commands or tools within the Docker CLI. Therefore, the core purpose of using the 'run' command is indeed to create and start a new container from a specified image, affirming that answer B is accurate.