Answer:
B. Project Gutenberg was the first to offer free books to anyone who could access the Internet.
Step-by-step explanation:
According to the given sentence, "Project Gutenberg was the first project to give an offer of an online tool that offered free books that cost nothing to anyone who could access or use the Internet", the most concise way to rewrite the sentence without losing important information is option B.
This is because, unlike the other options, B tells us the name of the project, and also adds that it is the first online service to offer books for free to anyone who could access the Internet.