I agree that "alphabetical order" could be confusing. However, the test makers did not
include "1" as an answer choice. I'm guessing they did this so that it would be clear to students that "alphabetical order" does not mean "consecutive alphabetical order." What happened when you did not see "1" as an answer choice? Were you able to re-adjust your definition of "alphabetical order" and get the correct answer?
If a question stem can be correctly interpreted multiple ways, then the test makers will remove that question from scoring. This rarely happens, but it does happen sometimes. The test makers work hard to ensure that questions can only be correctly interpreted one way. And they might give you hints like they did on this question by not giving you "1" as an answer choice.
If you ever find that 1) your answer choice is not one of the options, or 2) you end up with two correct answer choices, then you should re-read the question and and check your understanding of what is being asked.
And now you know that "alphabetical order" does NOT mean "consecutive alphabetical order" on this test. One less thing for you to worry about on test day.