That person is Andrew Mellon.
Explanation:
Contamination can have undesirable consequences in real experiments, some of them are related to the feelings that may arise in the research participants, the contamination bias reduces the differences between the research groups, and can cause a comparison between the treatments of each different group, the which can generate conflicts and rivalries on the part of groups that consider themselves to be inferior to others. These contamination-related problems can significantly interfere with the research results.
A humanitarian purpose means that an organization wants to help people in the most need, typically after a disaster, and it combats hunger, thirst, helps people cope with temperature (such us providing housing after an earth quake) and deals with any acute problems (but typically not wish long-term problems, such as development).
Answer:
I believe it would be C. to show how quickly cities grew after 1860 due to immigration, migration, and industrialization
Hope I helped :)
