(C) is correct because both authors agree with this statement. The author of passage A argues that "taking advantage of the knowledge that many others don't' have..doesn't make you a criminal; it means you've done your homework."(lines 13-15) . The author of Passage B similarly acknowledges that "success in the market can ..be gain by skill in analyzing the information and making good investment decisions." (lines 40-42).
(B) is incorrect because only the author of Passage B argues for market transparency. The author of Passage A argues that information should spread quickly and widely but it does not mean that is should be available to everyone at exactly the same time.
