TOEFL Listening: TPO-TOEFL听力TPO - T9I1O964E8I15NF9R$

What does the professor imply when he explains the washing and scraping methods that were used to remove ink from parchment surface? A. Washing made parchment more able to retain newly applied ink than scraping did. B. Washing was less effective than scraping as means of permanently erasing ink. C. The scraping method was used in the creation of the Archimedes palimpsest. D. Neither method completely erased the original text.