B strengthens the argument because it eliminates an alternative hypothesis.

The author wants to prove the theory wrong, but an alternative explanation that could make this theory right would be that there WAS a neutron star left behind by the supernova, but that the instruments haven't been able to detect it.

This hypothesis is eliminated by B, which tells us that neutron stars much farther away have been detected before; i.e. that if a neutron star had been left behind by the supernova, they would have found it.

Thank you so much for this explanation, I could not figure out what was tripping me up and why A was wrong until I read this!

I think that what tripped me up with this question was thinking that answer choice C is saying that the ants generally don't leave behind the pheromones.

But I think what the answer choice is actually saying is that sure, maybe these Saharan ant species leave behind the pheromones in the afternoons. (Recall that they do this because they want to use the pheromones to guide themselves back to their nests later). But since we know that all pheromones evaporate when the temps are >45C, and we know the temps are typically >45C in the Sahara during the afternoon, we can say that the ants probably don't use the pheromones to guide themselves back to their nests (since they'll have all evaporated).

The alternative would be an atypical afternoon in the Sahara with temps <45C, when ant species leave their pheromones behind as usual, and then use the pheromones to guide themselves back to the nest (which supports the use of the word "generally" in answer choice C).

I fell for answer choice E, and while I understand the content issues with that answer ("forms of exercise" instead of jogging, "severity" instead of # of injuries), I was confused by the decision to eliminate E due to the answer choice only going against the stimulus. In the first theory and approach lesson, wasn't one of the strategies to identify correct answers for Weaken questions to explain phenomena with an alternative hypothesis? Would this strategy only be effective if a stimulus was presenting a causation hypothesis, rather than refuting it?

I got this one right! .........but it took me 8 minutes :/

How would you generalize the method of analyzing statements containing "only"? I see that "only" is listed as a necessary indicator- in which the necessary condition would immediately follow the word "only"- but I can think of examples in which this would not be the case. For example, "I only go to work on Mondays" would be diagrammed as W --> M, rather than M ---> W.