Question: Which of  the following method requires the system to keep more information about the state of all running processes to break the deadlock in Resource Preemption

Answer:

Since, in general, it is difficult to determine what a safe state is, the simplest solution is a total rollback: abort the process and then restart it. Although it is more effective to roll back the process only as far as necessary to break the deadlock, this method requires the system to keep more information about the state of all running processes.