_____ is a unique identifier created by database management system to identify…

In database management systems, transactions need to be ordered to ensure consistency and isolation. A timestamp is a unique value assigned to each transaction to represent its relative start time. This helps in concurrency control mechanisms like timestamp ordering. Timestamps are generated by the DBMS and are used to determine the sequence of transactions. Other options like spoofing, shadow paging, and deadlock are unrelated to this purpose. Spoofing is a security attack, shadow paging is a recovery technique, and deadlock is a concurrency issue. Therefore, the correct term is timestamp.