The platform layer supplies the development environment and operational tools required to build, customize, deploy, and manage generative AI solutions. It connects foundation models and infrastructure with developers and organizations creating applications. Google Cloud’s Vertex AI is an example: it provides access to models, prompt-design tools, tuning capabilities, evaluation services, deployment facilities, and model-management functions. Option A describes the application layer, where end users directly consume AI capabilities. Option B more narrowly describes access to the model layer rather than the complete function of a platform. Option D describes the infrastructure layer, which supplies processors, storage, networking, and other computational resources. Therefore, providing tools for interacting with models and building and deploying AI solutions is the platform layer’s defining function.