An engineer wants to verify that an NVIDIA GPU is accessible inside a Docker container...

The correct command is docker run --rm --gpus all nvidia/cuda:12.4.6-base-ubuntu22.04 nvidia-smi. With the NVIDIA Container Toolkit installed and Docker configured, the --gpus all flag is the standard way to expose all available NVIDIA GPUs to a container. Running nvidia-smi inside the CUDA base container confirms that the container can see the host GPU driver stack, GPU devices, and NVIDIA runtime integration. Option A is incorrect because --runtime=docker is not the correct NVIDIA runtime configuration and does not request GPU access. Option B uses a plain Ubuntu container, which normally lacks the NVIDIA user-space libraries needed to run nvidia-smi. Option D uses an NVIDIA CUDA image but does not include the --gpus all flag, so Docker will not automatically expose GPUs to the container. In NVIDIA AI infrastructure, this validation is a basic control-plane and container-runtime check before running AI workloads through Docker, Kubernetes, Slurm containers, or NVIDIA GPU Operator-managed environments.