Final Answer:
Amelia Earhart did not contribute to solving the problem of spatial disorientation. The correct option is D.
Step-by-step explanation:
Spatial disorientation, a significant challenge in aviation, refers to a pilot's inability to accurately interpret aircraft attitude, altitude, or motion relative to the Earth's surface. Major Carl Spaatz, a., was a prominent figure in aviation history, known for his contributions to airpower and leadership. An autogiro, b., is a type of rotary-wing aircraft, but it does not represent an individual contributor. "An apprentice," c., is not a specific individual but a general term. Amelia Earhart, d., while an accomplished aviator, did not directly contribute to solving the problem of spatial disorientation. Her contributions were more focused on breaking aviation records, particularly in long-distance flights.
The correct option is D.