I was also confused on this answer choice, but the way I grew to see it is that Sibley's claim that "we must limit the number of degrees we choose to 'recognize' by name" is actually his descriptive reasoning for the arbitrary method of assigning species rather than a prescriptive suggestion for what ornithologists should do.

That would help explain why answer choice C is an improper inference. We have no evidence that Sibley suggests this approach, we just know that he's aware that it can cause a "slippery" classification. This in turn helps support answer choice E.

I hope that made sense!

#feedback #help

Hi! I've been having trouble accessing the answers for drills that I complete through the printable option of test-taking. Once I click "see PDF," the current tab is replaced by that PDF and I am unable to go back to that same drill to see the answers. The button doesn't allow you to open the PDF in a new tab, and you can't duplicate the tab to see the answers in another spot.

So basically, for me, there's no way to easily see the correct answers after I've taken a printable drill since returning to the drill tab just automatically starts the process of creating a new drill set.

Is there a way to resolve, reconcile, or explain this? Thanks :)

Yes!