The manager at Publix recently received information that customer satisfaction dropped at noon due to overcrowding in the checkout aisle. As a result, the manager went to the main floor to record the number of customers waiting in aisles 1-10 at noon. Which of the following choices would be an accurate description of the way the "number of customers" is used in this data set?

a. individuals for the data set

b. continuous qualitative variable for this data set

c. discrete qualitative variable for this data set

d. qualitative variable for this set

e. continuous quantitative variable for this data set

f. discrete quantitative variable for this data set