The correct answer is B (image). According to the Azure Machine Learning Python SDK v2 documentation and the community discussion with the highest upvotes (17 upvotes), when defining an environment from a Docker image, the 'image' parameter should be used to specify the Docker image name. The 'build' parameter is used when defining an environment from a Dockerfile, not from an existing Docker image. The community consensus strongly supports 'image' as the correct parameter, with detailed reasoning that aligns with Microsoft's official documentation.