Good question. This passage is tricky as it includes a lot of extraneous information on a confusing topic, and is thereby designed to throw you off the right answer.
(D) is correct. The question stem asks about present copyright laws. Therefore, you are looking for mentions of present/current/today's copyright laws in the passage. At line 20 the passage states "....since current copyright laws give owners of intellectual property the right to sue a distributor of unauthorized copies of their material even if that distributor did not personally make the copies." Therefore, we know that present copyright laws allow owners to sue distributors, and therefore that an author can sue a distributor.
(C) is incorrect. This passage does not discuss profits, but rather talks about ownership concepts apart from money. Additionally, there is no section of the passage which mentions present copyright laws prohibiting any type of action.
