STIMULUSArgument; not fact set
Premise 1: There are 70 to 100 Florida panthers alive today.
Premise 2: This represents a very large increase over their numbers in the 1970s
Counter-premise 1: Their current habitat is not large enough to support any more of these animals, however.
Conclusion 1: but their population must reach at least 250 if it is to be self-sustaining.
QUESTION STEMMust Be True
So, flow of information must be only from Stimulus to Question stem, i.e., assume everything said by the author to be true but do not assume anything additional that does not fall under the umbrella of ideas mentioned in the stimulus.
ANSWER CHOICES(A): "Quality" has not been mentioned anywhere in the stimulus. This is therefore, out of scope.
(B): Stimulus mentioned "...at least 250" for the panther population to become self-sustaining. This option on the other hand, states a certainty that if it "...ever exceeds 250, it will be self-sustaining". Author used the word "at least" to indicate that the number could be more based on other, unstated factors. However, the answer choice uses the word "will" - if this number "ever exceeds" 250. Never ignore the word play!
(C): Correct option - First, this is an answer choice that does not being in new information. Second, this answer choice could easily be created by combining ideas given in the Premise 1, Conclusion 1 and Counter-premise 1. Their current population is between 70 and 100 - for population to be self-sustaining it has to be "at least" 250 (could be more based on unstated factors) - current habitat is not large enough to support "any more" of these animals.
(D): "...will never increase" is a strong word play which had not been used in the stimulus for the presented idea. Stimulus only concludes that for the panther population to be self-sustaining, it must at least be 250, and the current habitat cannot allow any more of these animals.
(E): Could be true or could not be true. Answer choice however "Must Be True".