In Workday, a period close requires:

In Workday, a period close requires ledger account certification because this process ensures that all entries within the ledger are accurate and validated before the period is officially closed. Ledger account certification involves reviewing all account balances, verifying that transactions have been recorded properly, and ensuring compliance with accounting standards and organizational policies. This step is crucial as it confirms that financial statements can be produced based on the finalized data, providing a clear and reliable picture of the organization’s financial position.

The other choices do not represent necessary steps for a period close in Workday. External system reconciliation might be applicable in some situations but is not a requirement for closing the period itself within Workday's framework. Manual review of each transaction could be overly cumbersome and is not a standard closure procedure because Workday typically automates checks to streamline the process. Finally, while deletion of unapproved journal entries might be part of general maintenance, it is not a mandated step in the closing process, as unapproved entries would typically need to be addressed or corrected rather than deleted without review.