Answer:
Population.
Explanation:
When conducting a study, we say that the population is the complete set of people with some specific characteristics from which a sample will be taken.
A sample is the subset that is taken from the population and the sample is the one that is actually selected for study purposes.
In this example, Professor DeVries interviewed 50 of the school students (sample), thus, all the children attending the school would be considered to be the population since the subset of 50 students was taken from it.
