Which Google Cloud service provides a unified platform for building, deploying, and managing ML models?

Correct answer: Vertex AI

Option D is correct because Vertex AI is Google Cloud's unified, end-to-end machine learning platform that consolidates services for data preparation, model training, hyperparameter tuning, deployment, and model management under a single managed environment, including MLOps capabilities like Vertex AI Pipelines and Model Registry. Option A, TensorFlow Extended (TFX), is an open-source framework for building ML pipelines that can run on various backends; it is not a managed Google Cloud platform service in the same integrated sense as Vertex AI. Option B, BigQuery ML, allows users to create and run ML models directly within BigQuery using SQL queries, but it is scoped to in-database analytics rather than a full-lifecycle ML platform. Option C, Cloud AutoML, was a set of AutoML products that have since been incorporated into Vertex AI, and as a standalone answer it describes only a subset of capabilities rather than the unified platform.