Final answer:
Under multiprogramming, the turnaround time for short jobs is generally shortened as they can be executed quickly, optimizing system responsiveness for these jobs. Therefore, the correct answer to the question is a) Lengthened; Shortened
Step-by-step explanation:
The subject of this question refers to multiprogramming, a method used in operating systems to handle multiple processes (or jobs) at the same time. Under multiprogramming, the turnaround time for short jobs is generally shortened, because these jobs can be quickly executed and rotated out, allowing for more efficient use of the CPU. On the other hand, the turnaround time for long jobs is often lengthened as they spend more time waiting for their turn to use the CPU while shorter jobs are prioritized. Therefore, the correct answer to the question is:
a) Lengthened; Shortened
Under multiprogramming, a job's turnaround time, which is the total time from submission to completion, is optimized for different lengths of jobs. By allowing shorter jobs to be completed faster, the system improves their responsiveness. However, this approach may lead to longer jobs having extended waiting times, thus increasing their turnaround time.