Answer:
Philip Danforth Armour
Explanation:
He founded the meatpacking company "Armour and Company" in Chicago in 1867, which matches the American businessman and 19th century parts of your question. I hope this helps!
Calendar making.
Both used the sun to track the movement of the seasons and time very accurately with intricately made solar calendars using markings made on temple walls.
The answer is D, because it states it in the text above. Before wasting your points, read the text thoroughly!!