TOEFL Listening: ETS-TOEFL听力机经 - U307H39GW5BTQE49P$

What is the professor's opinion of Joseph Niepce's contribution to the invention of photography? A. Niepce would have made more progress if he had kept his methods a secret. B. Niepce should be acknowledged as the coinventor of the daguerreotype. C. Niepce deserved more support from his colleagues. D. Niepce should not have claimed the ideas of other inventors as his own.