Answer: AWS Pricing Calculator

## Explanation The correct answer is **AWS Pricing Calculator**. **Why AWS Pricing Calculator is the right choice:** - AWS Pricing Calculator is specifically designed to help users estimate the costs of AWS services before actually using them - It allows you to model different scenarios and configurations to get accurate cost estimates - For data transfer scenarios, you can specify the amount of data, source/destination regions, and other parameters to get a detailed cost breakdown **Why the other options are incorrect:** - **Cost Explorer**: This is for analyzing your actual AWS spending and usage patterns after you've already incurred costs - **AWS Budgets**: This is for setting spending limits and monitoring actual costs against those limits - **AWS Trusted Advisor**: This provides recommendations for cost optimization, security, and performance improvements, but not cost estimates for specific planned activities **Key takeaway**: When planning data transfers to S3 and need cost estimates beforehand, AWS Pricing Calculator is the appropriate tool to use.

Author: Ritesh Yadav