I remember this Qbank question, and I definitely recall getting confused/annoyed about it because there are so many reasons why I think Qbank is wrong.
1) I've had some experience and training in ethics (and specifically about advance directives) and I can tell you that I was taught what FA says--that a durable power of attorney for healthcare is always better than a living will, because what is said in a living will is narrow in scope and rarely applies perfectly to a real-life situation.
2) The Qbank answer does make a good point about the living will being more recent and thus possibly more relevant. However, even though I haven't seen many actual advance directive forms, all of the ones I have seen include both an area for a person to specify who they want to have DPAHC and an area for them to fill out a living will. So, its kind of hard for me to see how the situation could exist where someone who appointed a DPAHC w/out filling out a living will 2 years ago could have done a living will 1 month ago without addressing the issue of whether she wished to continue with the same DPAHC designee or get rid of it. I would assume that if she did not make any effort to rescind her daughter's status as the DPAHC appointee--which Qbank says nothing about--then that means she approves of her daughter continuing to have DPAHC (if anyone knows if my assumption is right or wrong, please let me know). Of course, Qbank doesn't really go into enough detail about this for us to figure it out, which brings me to my next objection...
3) Many ethics questions do not have clear answers and should not be asked as multiple choice questions. The point of ethics is that most answers need to be discussed and be tailored to the individual and aren't black or white. In this case, more details than Qbank supplies are needed, and it is really hard to give an answer when in real life (even in an emergency situation) you would never have so little information about the situation. Even if someone wrote a living will 1 month ago, you still have to know what exactly it says in there and what the person's situation currently is (requiring temporary or long-term intubation) to know if it applies--the timing of the living will isn't the only factor determining its applicability. Which is why DPAHCs are preferred over living wills--because the DPAHC designee can tailor their treatment recommendation to the situation--although you still need to know if the DPAHC designee understands their role and is truly acting in the patient's best interest and not for other reasons. In real life, both the living will and DPAHC would be considered, and you would want to make sure the daughter knew about the living will and could explain why she was advocating for a treatment that her mother did not seem to want a month ago. I know that this is a little off track from the OP's question, but I think it demonstrates why you have to take ethics questions with a grain of salt. Multiple choice ethics questions are hard to design well, and this Qbank question is not a well-designed one, although thankfully the actual questions on the boards seem to test ethical concepts a little better.
So, to summarize my answer to your question after that long explanation, in real life and in FA: DPAHC>living will>nothing. Go with FA over Qbank. I don't know what the boards use as a source for their ethics questions, but I would hope it would be clinical ethicists who practice by the same principles that govern the practice of the ethicists I have worked with and been taught by, and which incidentally are also in FA.
