Bibles are rare, expensive, and only written in Latin-->low literacy rates-->questionable practices of the church-->Gutenburg's invention-->???

Which of the following is the logical next step in this progression?

a
The Bible was printed in vernacular languages leading to greater criticism of the church.
b
Maps could be updated and printed more regularly to improve navigation.
c
The Catholic Church printed messages from the Pope encouraging missionaries to travel and gain converts.
d
Universities used printing presses to create huge libraries.