In your role at a manufacturing company, you're tasked with predicting failures of a high-value machine equipped with multiple sensors. Historical hourly sensor readings and failure events are stored in BigQuery. Your goal is to predict if the machine will fail within the next 3 days to schedule timely maintenance. The solution must consider cost-effectiveness, scalability for thousands of machines, and compliance with data privacy regulations. What are the optimal data preparation and model training steps? Choose the best two options.