TOEFL Listening: ETS-TOEFL听力机经 - P0UWH415K20E8JCFP$

Why does the professor mention an artistic movement called impressionism? A. To point out how the development of photography influenced art history. B. To explain why a long-established art movement continues to be popular. C. To help explain how photography evolved as an art form, D. To discuss a factor that led to improvements in cameras.