Answer: Amazon SageMaker

Amazon SageMaker is the correct choice because it provides fully automated model tuning capabilities through features like SageMaker Autopilot and SageMaker Hyperparameter Optimization (HPO). **Why Amazon SageMaker is optimal:** - **SageMaker Autopilot** automates the entire machine learning workflow, including data preprocessing, algorithm selection, feature engineering, and hyperparameter tuning, with minimal manual intervention. - **SageMaker HPO** uses Bayesian optimization to automatically search for the best hyperparameters, improving model performance efficiently. - These tools align with the requirement for "fully automated model tuning" by reducing the need for expert knowledge and manual configuration. **Why other options are less suitable:** - **A: Amazon Personalize** is a managed service for building recommendation systems, not for general-purpose model tuning. - **C: Amazon Athena** is an interactive query service for analyzing data in Amazon S3 using SQL, not for machine learning model development. - **D: Amazon Comprehend** is a natural language processing service for text analysis, lacking automated model tuning features for predictive modeling. Thus, Amazon SageMaker best meets the requirement for automated tuning in creating a predictive model for customer satisfaction.

Author: LeetQuiz Editorial Team