PT21.S2.Q13 - astronomers have long thought that

yhchoi1687

http://7sage.com/lsat_explanations/lsat-21-section-2-question-13/
I wonder whether this is really necessary assumption question.
Isn't this most strongly supported question or anything else?
There's no clear conclusion in the stimulus and although I negate (D) I am not sure if I can entirely wreck the argument.
I got this question right, but just wonder whether this question is properly categorized.

c.janson35

It's a most strongly supported type of question, meaning 4 answers will have no support and 1 answer will. Negating choices is a strategy used to find necessary assumptions, not inferences. You are right in saying that there is no conclusion because this question is not an argument. It is a set of facts that initially posits a cause and effect relationship between Pluto and Neptune, and then goes on to explain that Pluto doesn't nearly have the gravitational pull that astronomers once thought because of how small Pluto was found to be. So, the newly found evidence is weakening this cause and effect relationship by removing what was once thought to be the cause; the effect, though, remains--which is what D is telling us.