This is a flaw question. The first sentence sets us up, but after reading I focused on the following sentences where we got more information.
“This book has received much positive attention from the popular press but has been severely criticized by many professional archeologists for being to extreme.â€
After reading this, try to ask yourself, “why might this be?†Be thinking ahead and thinking critically about your argument.
Next, we are given a strong concluding statement, that “Montgomery’s views do not deserve negative appraisal...â€
The second part of that sentence answers “why†for us:
...â€since those views are no more extreme than the views of some professional archeologists.â€
Wait a second...did they ever tell us that the extreme views of those other professional archeologists weren’t deserving of negative appraisal? No, they didn’t. In fact, it’s possible that those other views are just as worthy of criticism because they are also extreme.
Hopefully this critical pushback to the stimulus helps reveal why answer choice A (It fails to establish that professional archaeologists’ views that are at least as extreme as Montgomery’s views do not deserve negative appraisal for that reason.) is the right fit. Feel free to tag me and let me know if you have any more questions!