Who taught many of the current researchers as a professor at Cornell University?

The correct choice is based on the significant influence that Dr. Roger Morse had on the field of beekeeping and honeybee research. As a longtime professor at Cornell University, he played a crucial role in shaping the education and training of many researchers in the field. His contributions to beekeeping, including research on honeybee behavior, hive management, and pest control, have left a lasting legacy that continues to impact current studies and practices. His teachings and mentoring provided foundational knowledge and inspired many students to pursue careers in apiculture and related research areas.

While other individuals mentioned have made significant contributions to beekeeping, particularly Dr. Clarence Collison who wrote extensively, Dr. David Tarpy who is currently active in research, and A.I. Root who was pivotal in the early development of beekeeping literature, none have had the widespread influence on training researchers at Cornell University during the time that Dr. Morse was present, which is why he stands out as the most notable figure in this context.