Answer:
d) The data are quantitative because they consist of counts or measurements.
Explanation:
The number of cases of flu treated at a certain hospital in different years consists in integer numbers (there cannot be 108.4 cases of flu treated in one year, just 107, 108, 109, etc).
Therefore the date are quantitative because the data consists of numbers which are counts of a certain number of individuals who were affected by the flu during different years.