choose the word or group of words that best completes each of the following sentences:
The research was carried out _________a sample population.
- over
- in
- with
-
on
The correct answer is: D
Explanation
The preposition "on" is the most suitable choice in this context because when conducting research, we often say it is carried out "on" a sample population. This usage conveys the idea that the research is performed concerning or with regard to a specific group of individuals, which is the sample population. So, the complete sentence implies that the research was conducted with a focus on or involving a particular sample population.