Which AWS service is designed to help build, train, and deploy custom machine learning models?

Amazon SageMaker is the correct answer because it is a fully managed service that provides every developer and data scientist with the ability to build, train, and deploy machine learning models quickly. It offers a comprehensive set of tools and integrated development environments (IDEs) for the entire ML workflow. Amazon Personalize is an ML service that helps developers build applications with the same machine learning technology used by Amazon.com for real-time personalized recommendations. Amazon Comprehend is a natural language processing (NLP) service that uses machine learning to find insights and relationships in text. Amazon Forecast is a fully managed service that uses machine learning to deliver highly accurate forecasts. While these services use machine learning, they are specialized for specific tasks rather than providing a general platform for building, training, and deploying custom models.