The correct answer is Amazon SageMaker. It is designed as an end-to-end machine learning service, which facilitates the entire process from model building to deployment. Amazon Lex, while it is a service that uses machine learning, it is specifically for building conversational interfaces using voice and text. Amazon S3 is a storage service, not a machine learning service. AWS Glue is a data integration service used for preparing and loading data for analytics, not for building machine learning models.