What can the reader infer the author means when he says that newspapers were not truly modern until after the invention of movable type? a) to be truly modern, newspapers must cost more than a simple gazetta and have a sizable subscription base. b) to be truly modern, newspapers needed to be strictly about news and not contain opinions or advertisements. c) a modern newspaper is printed many more times than previous newspapers--and still is relatively cheap to buy. d) modern newspapers have editorial staff and hires an army of reporters to investigate every case of legal wrong-doing.