Why is Atlanta's longest serving mayor, William Berry Hartsfield, known as Atlanta's "father of aviation"?

AHe was an accomplished pilot who began Delta airlines.

BHe was a colleague of airplane inventors Orville and Wilbur Wright.

CHe developed the C5 mass transport airplane for Georgia's Lockheed Aeronautical plant.

DHe believed that an airport for Atlanta would be a key to the city's economic prosperity.