Let me initially ask you a question in return:
What's the #1 thing you should be looking out for when you're reading the answer choices of an
Inference question?
If you can't answer that easily/immediately, you might be making Inference way harder on yourself than it needs to be. Most answers are wrong because they say something
too extreme.
Extreme words don't have to be wrong; if the information said something extreme, then a correct inference could as well. But most of the time, the answer choice is phrased more strongly than the actual information provided.
(E) says that social science is
invariably "unscientific".
As you said, the info talked about social science not being precise and not being universal (hard to generalize); these are NOT ideal scientific qualities.
But it said that "laws of social science
often are imprecise." "laws that only narrowly apply are
typically the only ones possible for social science."
We can't get
invariably from that.
== other answers ==
(A) This is supported by the first sentence. Since 'precision' and generality' are virtues an ideal scientific law should display, it's fair to say that having those qualities is better than lacking them.
(B) This predicts the outcome of a hypothetical statement (super sketchy). We can't support that social sciences would BENEFIT from a change. More conversationally, this answer choice acts as though the author's goal was to encourage social sciences to become more like physical sciences. But the author uses phrases like "have to use" / "the only ones possible" to indicate that social sciences is stuck doing certain things in an un-ideal fashion.
(C) Just as it was with (B), the 'should' in this answer contains opinion the author never expressed. We can't find wording suggesting the author thinks social science SHOULD be more precise. He says the ideal is precision, but "the nature of social science laws" is that they often "HAVE to use terms that are imprecise, such as 'class'."
(D) Just as it was with (B) and (C).
Notice that the logic behind the whole group of trap answers is the same: an overreach that takes what the author was saying and turns it into a 'complaint', 'a suggestion', 'a condemnation'.
Try not to insert tone that is not expressly written on the page.
The author might actually BE a proud social scientist. These words could just as easily be spoken by someone admitting, while accepting, the limitations of his/her field.
Hope this helps.
#officialexplanation