TOEFL Listening: TPO-TOEFL听力TPO - 1MV18N804PB2X984R$

What does the professor imply when he says this: A. He is not convinced the Egyptians made the first synthetic pigment B. He is impressed by the Egyptians' accomplishment. C. The process the Egyptians used is now widely known. D. The Egyptian pigment was of lower quality than today's pigments.