"Independent" is too extreme. The data shows that small countries can be viable, which tells us a large population isn't required for viability. It does not tell us that population is independent of viability, which would mean population size has no effect on viability at all.

To see the difference, consider an analogy. You don't need to score a 180 on the LSAT to get into law school. True. But it doesn't follow that your LSAT score is independent of getting in. Even though small countries can be viable, population could still play a role. A country of fifty people probably couldn't sustain a modern economy. The stimulus doesn't rule that out, so we can't claim that viability is independent of population size.

The stimulus tells us about countries with populations at or below 7 million, not about countries with populations above 7 million. We have no information about countries like the United States, India, or Brazil. The word "ensures" is also extreme. Even if every country above 7 million happened to be viable, "ensures" claims a guarantee, which is more than the data establishes.

Strongly supported. Israel, Ireland, Denmark, and Finland have viable economies despite populations at least 25% smaller than 7 million. Those four countries are counterexamples to the idea that viability requires at least 7 million people. So viability doesn't require a population of at least 7 million people.

(D) baits you by using words from the first sentence. The phrase "level and rate of growth of aggregate output" appears prominently in the stimulus, so the answer feels familiar. But the stimulus only tells us this is the most significant indicator of viability. It never tells us what causes or contributes to aggregate output in the first place. Population could be a major contributor, a minor contributor, or completely unrelated. We have no idea.

(E) takes both sets of indicators from the stimulus (aggregate output on one side, unemployment and inflation on the other) and asks us to compare how much population affects each. But the stimulus never establishes that population affects any of these measures.