What term refers to a mechanism in a database that can fire actions after data modifications or to prevent changes?

• A. Update
• B. Trigger
• C. While Loop
• D. Xml

Answer: (B)

A database trigger. A trigger is a database object that automatically runs in response to certain events on a table or view, such as insert, update, or delete. It can fire after data is modified to perform follow-up actions like logging, enforcing rules, or cascading changes. It can also be set to run before a modification so you can validate data and prevent the change by raising an error or stopping the operation. This dual ability to react to modifications or to block them fits the description perfectly. In contrast, an update is just a modification statement, a while loop is general programming control flow, and XML is a data format, not a reactive mechanism in the database.