This might not be popular, but personally "Where" is probably my least favourite question mmm...
Because it's simpler than Why or How, but to answer it, many times you have to explain quite a lot for people to understand mmm...

This is indeed another odd question. Last time it was the "which organ body would you choose" poll.

I think it can be annoying or not depends on how the question elaborated, who gives the question, and when the question was asked.

The question of when can be annoying for me, especially if it used by either family or neighbors to ask, "When are you going to get a job?" Or "When are you getting married?" And etc.

Why? Life isn´t a mystery novel. Some Men Just Want To Watch The World Burn is a valid answer.

I generally like answering questions... But due to personal and professional things don't like to be asked "When?"
It will be done when it will be done, stop bothering me with ETAs and such

I think it mostly depends on who is asking the questions but for me, it's why definitely.
Sometimes it just comes off as too extra or someone who doesn't want to think much, you know? It's not always the case, so as I said, depends on who's asking me that question and in what tone ww( ･ั﹏･ั)

"What were you eating under there?"
"Under where?"

How I don't know how to explain things! I don't know how things work! I don't have any brain cells please don't ask me!!

‘When’ has the most potential to be annoying IMO since I often hear it in an oblivious and whiny context (when will I get there). I wouldn’t say that any are annoying by nature though.

On MU, only "where" is not allowed.

I think back to my childhood. When I wanted to be annoying, I would always ask "Why?" to everything.

This question makes no sense. How/why would those be annoying?
Granted, the full question may indeed be annoying, but not due to any of those words.

Questions that set out to prove a negative.

I’ve always liked MU’s polls but surprisingly this one is my favorite so far.
My pick is “how”, I don’t even know *how* to explain it but if somebody asks me a “how” question and I have to explain whatever they ask me in a detailed manner, I’ll be annoyed. Which doesn’t make sense bc SOP is important. BUT I’LL STILL BE ANNOYED!!!!

I like “why” though, hence it surprised me that people chose it the most. When I saw the result I was like; “bUT WHY?!!!” Why did they pick why? I want to know the reason. I want to understand them better.

I wonder why "why?" is so far in the lead (followed by "what?" no less!). For "why?" there's always the response "why not?"

Honestly, "why?" and "what?" are my favourite questions. (Okay, my preferred subjects are showing here, but still.) Yes, "why?" can easily go on indefinitely, but if someone keeps asking it (which is annoying for any question, to be sure), "why not?" usually solves the issue. Truth be told, I find "how?" "where?" and "when?" more annoying, but then again, I am decidedly not mechanically-minded and am pathetic at rote memorization (that, and I find recitation of facts incredibly boring).

Apart from people asking something, anything, incessantly, I'm guessing that which question annoys people most depends on how your mind works / your skill-set. E.g. in my case, questions of how something occurred (beyond the bare bones) and questions of specifics I may or may not remember are far more annoying than questions of quality ("what-ness," otherwise known as quiddity) and questions of causes / reasons (the whys). Someone with the opposite skill-set would probably have the opposite situation, no?

Of course there are also plenty of people who're bothered by the lack of a definitive answer (one of my siblings is a little like that), possibly more than the number of people bothered by the answer being definitive (like me) — well, it isn't a bad thing either way. People who are generally bothered by answering "I don't know," are another matter altogether. Although, sometimes, that situation can make you feel stupid, i.e. when the information you can't recall or don't know is supposed to basic (which is me about a third of the time — what's the word for __ again?).

Of course, in all of this, I'm just speaking generally and of generalizations.

Other than that, I'm in agreement with zarlan.

So many people chose "why?", and I think I understand their reasoning, but I personally chose "how?"

"How?" is simultaneously the most difficult question to answer, and sometimes there isn't even any answer to it, which makes it super annoying.

Even so, it's probably the most important, as understanding how things work in our world can lead to great advances, not only in scientific achievement, but also in an individual's own life.