A researcher measures two individuals and then uses the resulting scores to make a statement comparing the two individuals. For each of the following statements, identify the scale of measurement (nominal, ordinal, interval, ratio) that the researcher used.

a. I can only say that the two individuals are different.
b. I can say that one individual scored 6 points higher than the other.
c. I can say that one individual scored higher than the other, but I cannot specify how much higher.
d. I can say that the score for one individual is twice as large as the score for the other individual.