I think the method here is to stick the core of the argument about biological species concept. Flick back to the only line where the author explicitly discusses what its proponents say (para 1): if you interbreed, same species, if you don't, then you aren't. The only one that really touches upon this core issue is (D). The rest seem far-off inferences which could be true but can't be attributed as direct beliefs of the proponents of this concept.

You are right that they group very similar species together, but if you shift focus to WHY they do that, it makes (D) more provable. They group them together not because they are similar but because they interbreed, that's it. That's what their opinion is based on, not the visual similarity. The latter is just somewhat of a consequence.

Hope that helps!

Algorithms can be copied without it falling under copyright law, since they are universal laws/principles like principles in any science. The specific program used to express an algorithm can and should be under copyright law. This was the author's argument in the passage, and the specific wording in (C) goes against their argument.

So, what the author believes is the opposite of (C) - sequences should be copyrightable no matter whether they're using a new or old algorithm, since algorithms are just principles that can't be owned or copyrighted.

For me, (D) is incorrect not just because it is a stretch, like you and others have said above, but also because of the way 'deception' is used in the argument.

Medicine A has no direct known sleep inducing properties. Hence it is deception to give it in order to help sleep, and hence he is in violation of the ethics code. It does not matter whether the doctor BELIEVES it might have sleep inducing properties or not - even if he does believe so because many other hospital staff administer it to patients for sleep, he is still unintentionally deceiving the patient.

The argument's implicit assumption says 'no sleep inducing --> deception' whether he intentionally deceives (knowing it can't help the patient) or unintentionally deceives (looks at other staff and thinks oh it might help sleep, but he's still wrong).

The only way to show he did not defy the principle of avoiding deception, then, is to show it DOES have sleep inducing properties. This is what answer choice (C) shows.

Hope that helps!