Determine whether the data described below are qualitative or quantitative and explain why.

The area codes (such as 617 )of the telephones of survey respondents:

a. The data are quantitative because they consist of counts or measurements.
b. The data are quantitative because they don't measure or count anything.
c. The data are qualitative because they don't measure or count anything.
d. The data are qualitative because they consist of counts or measurements.