Thanks for your question, Angie, and welcome to the Forum!
While it is true that the passage author spent a long time on the etymology of the word "profession," we have to look beyond the remainder of the first paragraph to answer Question 24. Instead, we need to look at the function played by the author's rhetorical question.
To think about the function played by that question, think about what the author is trying to get across. The ultimate distinction the author draws is between that of a profession and a trade, or occupation. The author uses the etymology of the word "profession" to set up that conversation. So, while the a discussion of the origin of the word "profession" immediately follows the rhetorical question, the author use the question to introduce a larger idea.
Also, consider this. To pick answer choice (E), you are saying that we know something extrinsic to the passage. That we know the author has a fascination with the origins of words. While that may be true, it is not necessarily the case. All we know for sure from the passage is that the author discusses the origin of the word in order to "gain some illumination" (10-11) on the larger question at issue.
Please let me know if this helps. And, again, welcome.
Ron