Final answer:
The correct type of log record that indicates a transaction has been aborted is the 'Abort' log record. Option 3.
Step-by-step explanation:
In database systems, a log record is used to keep track of all the operations performed by transactions, to ensure data integrity and to enable the possibility of recovery in case of system failures. When a transaction is aborted, due to errors or because it doesn't satisfy certain conditions, an Abort log record is created.
This Abort record indicates that the transaction T has been rolled back, and all its changes that may have been temporarily recorded in the database must be undone to maintain the consistency of the database.
The correct answer to the student's question is 3) Abort.