Let's look at (B) and (D) as well as the argument.
We know that Harris is mad about the present state of endangered-species laws. Although they may protect traditional species, they don't currently protect hybrid animals that are the mixture of two species. Harris concludes that we should change these laws to include the protection of hybrid animals.
Vogel, on the other hand, disagrees. She says that if the independent source species of the hybrid are protected, then we can simply breed more hybrids through using the two independent species if the hybrids diet out and get close to extinction.
We're looking for a point at issue (disagreement) between Harris and Vogel. The correct answer choice will be supported by one of the speakers and will go against what the other speaker is saying. With this argument, we know that Harris and Vogel have opposing conclusions. Harris thinks that we should change the laws to add protection for hybrids, whereas Vogel doesn't think that hybrids need protection.
(B) says, "whether there are some species that are currently considered endangered that are not in fact in any danger"
Vogel makes the suggestion that some hybrids might not be endangered, but we can infer from the stimulus that a hybrid isn't considered a species. Additionally, Harris doesn't have an opinion on (B), so we can get rid of it.
(D) says, "whether there are some hybrids that ought to be protected by endangered-species regulations"
Harris agrees with (D), and provides the red wolf as an example. Vogel states that it doesn't make sense to make laws to protect hybrids, so they disagree on (D). Thus, (D) is the correct answer choice.
Does this make sense? Let us know if you have any other questions!
