Determine which of the four levels of measurement (nominal, ordinal, interval, ratio) is most appropriate for the data below. Choose the correct answer below.

a. The interval level of measurement is most appropriate because the data can be ordered, differences (obtained by subtraction) can be found and are meaningful, and there is no natural starting point.

b. The nominal level of measurement is most appropriate because the data cannot be ordered.

c. The ordinal level of measurement is most appropriate because the data can be ordered, but differences (obtained by subtraction) cannot be found or are meaningless.

d. The ratio level of measurement is most appropriate because the data can be ordered differences can be found and are meaningful, and there is a natural starting zero point.