B VS. C

Let's look at (B) and (C). (C) says, "Ethical inventiveness and technical ingenuity are never possessed by the same individuals." The issue with (C) is that it's telling us that there won't be people who're both happy and sad if the conclusion is true, but it's not helping us to conclude that some people will be happy and other people will be sad, so we can get rid of this choice. (B) says, "Politically powerful people tend to reward those who they believe are useful to them and to punish those who they believe are a threat." (B) looks great because we needed something to get us from opinion to result. (B) gives us the actions the the people in power take in order to bring about the result, so that's why it's correct.