Answer:
The correct answer is letter "C": weight the subgroup data to match representation in the population.
Step-by-step explanation:
In order to have an idea of how diverse a population is, samples of different groups are taken and compared to the overall number of individuals to find out what the distribution is among those groups. In the case, one group is left underrepresented, researchers tend to make a census of them to adjust their percentage of representation with the global population.