Answer: c. Ordinal
Step-by-step explanation:
An ordinal variable is one where the variable is used to categorize data in a qualitative way which can be ordered and ranked. For instance, in the case of schooling, the levels are: elementary, high school and college. Graduates from each level can be ranked in relation to each other.
A research survey therefore that has outcomes such as Poor, Average, Good, Excellent is using ordinal variables because these are qualitative and can be ranked in relation to one another.