Which edit to these sentences is necessary to correct a writing error? Once the printing press was invented, authors have been able to make copies of their works quickly. This meant that people could publish books and pamphlets more independently than previously.

A. Change "books and" to "books, and"

B. Change "Once the" to "Once, the"

C. Change "have been" to "were"

D. Change "pamphlets" to "phamplets"​