Quantitive data can be measured quantitatively

yeah

here's why :

In order to measure qualitative data quantitively, categorical variables are used. These type of variables are defined by a set of positive numbers, and each number is connected to a nominal category, which has been defined based on a qualitative property.

For example, if conducting a research about holiday patterns, one of the variables registered aims to measure the season in which people travel the most  hence the following categories are defined: spring (=1), summer (=2), autumn (=3) and winter (=4). This is a categorical variable. If it only had two categories it is denominated a dummy or binary variable (values: 0, 1).

a is your answer hope this ! : )

answer; the changing age structure of the population;