Answer:
d. Ordinal
Explanation:
The different levels of measurement were proposed by a psychologist named Stanley Smith Stevens who has mentioned four sales or levels of measurement including ratio, nominal, interval, and ordinal.
Ordinal level of measurement: In research methods, the ordinal level or scale of measurement is described as the process that involves the "ordering of the given measurements". Ordinal data is the data that can generally be placed into any specific kind of scale of order. It is usually being placed on a specific scale.
In the question above, Professor Tilton was using the ordinal level of measurement.
