Answer:
A) Nominal Scale
Step-by-step explanation:
Nominal scale is a measurement technique in which data is arranged in table with labels. The nominal scale is useful with few or no numeric value which means when data is in non numeric form this method is best suited.
In the given scenario Professor Harris is considering to create questionnaires to identify the people living in urban, rural or sub urban settings. This is non numeric data and people are grouped based on demographics. This is an example of Nominal Scale.