Answer: C. In multiple places throughout the salad.
Step-by-step explanation:
For a potato salad you can eat about 2 hours after cooking if the food is kept under the temperature range of 40-140 F temperature. The refrigeration of salad is a good way to preserve the salad for long about 40 F. The hot salad can be reheated before 140 F.
The salad material may include different components other than potatoes which may have different cooling rates. Thus the temperature of the potato salad must be measured at different places.