A vs C?

C should be eliminated because it does NOT have to be true. Yes this is a "must be true" question, so any answer that could be true ought to be eliminated along with answer-choices that do not have to be true, not necessarily true and cannot be true. C states that "Most publishers will sell their own books individually and will not use distributors or retailers." Where in the passage are there statements strong enough to yield for the inference (inference because this is a must be true question) that more than half of the publishers will cut out the retailers? Also important to note that if part of there answer-choice is false, then the whole answer-choice should be eliminated. So although distributing PHYSICAL BOOKS is no longer needed under the new digitized model, we cannot assume that the publishers will not distribute the digitized copies. Finally, with respect to lines 15 through 21, where the idea of retail stores is being discussed. If you read closely, again, "shipping and displaying the physical books" will no longer be necessary, but we cannot infer from what answer-choice C states which is that publishers (most of whom) will [themselves] sell they own books and will cut out the retailers! In retrospect, C is an unwarranted inference!