Which command would you use to pull a Docker image from a registry?

The command to pull a Docker image from a registry is "docker pull." This command is specifically designed to download images from a remote repository, such as Docker Hub, to your local machine. When you execute this command, Docker connects to the specified registry, retrieves the image, and stores it locally, making it available for you to run containers based on that image.

Understanding the command's function is vital. "docker pull" allows users to specify which image they want, including any tags to indicate a specific version. This is essential for maintaining consistency in application deployments. The use of "pull" in this context indicates the action of retrieving something from a larger repository, which aligns with standard terminology used in software development.

The other options do not correspond to common Docker commands. For instance, "docker upload" does not exist as a Docker command, as Docker typically uses "push" for uploading images to a registry. Similarly, "docker fetch" and "docker retrieve" are not recognized commands in Docker’s command-line interface. Therefore, "docker pull" is the only accurate and effective command for this operation.