Answer:
a. Insufficient number of physical processor cores.
Step-by-step explanation:
Based on the information provided within the question it can be said that the most likely cause of this would be that there is an Insufficient number of physical processor cores . Therefore the few cores are having to deal with all of the information that needs to be processed, which they cannot handle. More cores would allow the information to be spread between them and the CPU load to be lowered.