The correct answer is B. Import Reported Time Blocks.

In Workday Time Tracking, when an organization needs to load legacy time entry data into the tenant for configuration testing, the appropriate Enterprise Interface Builder (EIB) is Import Reported Time Blocks. This EIB is specifically designed to bring in historical or external reported time entries so that organizations can validate how Workday processes time calculations, overtime rules, validations, approvals, and downstream integrations using realistic data.

This is especially useful during implementation or testing cycles when the team wants to confirm that configured time entry templates, time calculations, and administrative processes behave correctly with actual time data patterns from the legacy system. By importing reported time blocks, Workday can apply the configured rules and allow testers to compare expected and actual outcomes.

The other options are not intended for loading time entry history. Payroll Input is used for payroll-related input data, not for time entry blocks. Put Period Schedule is used to maintain or load period schedule information. Put Holiday Calendar is for holiday setup, not worker time records. None of those options load the detailed reported worked-time entries needed for time tracking configuration testing.

Therefore, the correct EIB for loading legacy time entry data into Workday Time Tracking is Import Reported Time Blocks.