Which sentence uses a formal tone most appropriate to a research paper?

A Dr. Roscoe's work sheds new light upon the life cycle of the silkworm.

B. We are so lucky to benefit from Dr. Roscoe's work on the life cycle of the silkworm.

C. Dr. Roscoe's groundbreaking work on the silkworm stunned all of us in the research
community

D. I think Dr. Roscoe is the most important researcher to study the silkworm in twenty years.​