I saw a quiz below.

All ______ for visitors' passes must be made in person at the security office.

(A) requested

(B) request

(C) requester

(D) requests

I thought 'All (which were) requested for visitors' passes musb ~'. So I checked (A) skipping other choices. But the right answer is (D).

I understand (D) can be a right answer.

But I can't understand why (A) is wrong. Can you explain what I'm misunderstanding?
Neither 'all requested for' nor 'all (which were) requested for' makes any sense to me, Erious. 'All' refers to what? In D, 'all' refers to requests.
Thank you for your answer.

Ah, if some sentences are ahead of that sentence, then (D) can be the answer?
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D is correct in any case.
I'm sorry that I'm confused with (A).

I wanted to say (A) not (D).
If you can imagine some previous text that makes A right, then please post it and we'll take a look.
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The text above, that's all. I just wonder whether if there's some previous text, then (A) can also be an answer.

Now I understand with your answer. Thank you !