Final answer:
The main difference between short term and long term schedulers is their execution frequency, with the short term operating more frequently and the long term less so.
Step-by-step explanation:
The primary distinction between the short term scheduler and the long term scheduler in operating systems is the frequency of their execution. The short term scheduler, also known as the CPU scheduler, makes decisions much more frequently, selecting which process in the ready queue should be executed next by the CPU. On the other hand, the long term scheduler, also known as the job scheduler, determines which processes should be brought into the ready queue from the job pool and is responsible for the degree of multiprogramming, which refers to the number of processes in memory. It operates less frequently compared to the short term scheduler. Hence, the correct answer to the question is c) The frequency of their execution.