Thanks for the question! Let’s take a look at the argument first. We’re told that Mayor Smith, who used to be opposed to nuclear power plant construction projects, now supports one. The argument then concludes that because of this, there’s good reason to believe that the nuclear power plant will be safe and should be built.
We’re then asked to find a flaw in the argument. It’s good to prephrase this kind of question. Note that one thing that sticks out immediately is there's that we don’t know why Mayor Smith opposed nuclear power plants back then, nor why she supports them now. Maybe someone bribed her and that’s why she supports it; if that were true, then the conclusion obviously doesn’t follow.
With that being said, let’s take a look at the answer choices. (C) tells us that the argument fails to establish that a consistent and outspoken opposition is necessarily an informed opposition. Is this a flaw in the argument? Let’s say that (C) is right, and that the mayor’s opposition wasn’t informed. Couldn’t that suggest that she was once informed, and now, having the correct information, switched sides? But if this were true, then that would support the overall conclusion: that the mayor was given new information to believe that the nuclear power plant at Littletown is safe and therefore should be built. Thus, (C) cannot be the flaw in the argument.
Let’s take a look at (E). (E) tells us that the argument doesn’t tell us why Mayor Smith used to oppose the nuclear power plant, or why she supports this one. This is exactly what our prephrase said. Mayor Smith could have changed her mind for a number of reasons: political compromise, a bribe as mentioned before, or maybe personal connections with the people building them. As such, it’s not necessarily true that she wants to build the power plant because she thinks it’s safe, and so (E) is the correct answer.
Hope this helps! Feel free to ask any other questions that you might have.
