Which of the following behavior symptoms is most indicative of thrashing in a computer system?

The system shows a consistent high level of CPU utilization, and applications run faster than usual.

The system frequently becomes unresponsive, but resumes normal operation after a short period without intervention.

The system experiences a steady state of high disk activity coupled with a significant slowdown in program execution despite low CPU utilization.

The system's memory usage is low, and applications are not demanding many resources, yet the system runs efficiently.