A retail company is planning to develop a machine learning model to predict customer churn as part of its strategy to improve customer retention. The project is in its initial phase, and the team is evaluating the critical steps necessary to ensure the model's success. Given the constraints of data privacy regulations, the necessity for scalable data processing, and the imperative for accurate predictions, which of the following steps is the most critical initial phase to guarantee the model's success? (Choose one correct option)