Thanks for posting,
kalindazhang!
So, while the question is asking for the
main point, remember that this is another way of asking what the
conclusion of the argument is.
First stop, argument core! We've to sort the premise(s) from the conclusion, and the background noise from the argument core itself. All that information about
politicians is background noise. The author is not making a case here, or backing up an argument. He's just laying out the situation as it stands
with politicians.
When he turns the camera to
political commentators, though, that's where things get interesting. The last three sentences are the argument core. The conclusion comes right away - unlike politicians, political commentators cannot be excused for mudslinging. Your paraphrase was spot on! The next two sentences both provide support for that conclusion.
PREMISE:
1) Political commentators should be engaged in sustained/serious debate
2) Personal attacks/mudslinging just cut off debate.
CONCLUSION: Political commentators can't be excused for mudslinging!
(B) gives us another valid paraphrase of the conclusion: Political commentators
should not mudsling!
The phrase "resort to personal attacks" just means the same mudslinging and personal attacks the argument was discussing. "Their opponents" means 'the opponents of the political commentators". So, this simply means that the political commentators should not mudsling (or personally attack) at the people who disagree with them!
Let's take a quick spin through the
incorrect answers:
(A) The conclusion is about political commentators, not politicians!
(C) The conclusion is about political commentators, not politicians!
(D) We never talk about the purpose of serious debate, just that it is what political commentators ought to be engaged in.
(E) The author never claims that voters ought to be more concerned. And again, our conclusion was about political commentators, not politicians!
Please let me know if this answered your question!