Thanks for the question! Just because the word “ethical” was used in the answer choice and the word “moral” was used in the stimulus doesn’t mean that the author questioned the ethical basis of an economic situation. Questioning the ethical basis would be doing something like questioning using child slavery in cocoa production or something. Here, we don’t have anything like that. The “moral” in the stimulus is like “the moral of the story,” not “morality.” And the answer refers to the “ethical basis,” which the moral in the stimulus wouldn’t be anyway.
Hope this helps! Feel free to ask any other questions that you might have.