Just to clarify:
If your quiz has not gone online yet, and the correction note is from an editor, then you do in fact need to resubmit the quiz after making the necessary corrections and marking the note appropriately.
But if your quiz IS online, and the correction note is from a player, then you do NOT need to take your quiz offline or resubmit it. Simply make the corrections (if necessary), mark the note (either "corrected" if that applies, or "not an error" with an explanation of why not), and leave your quiz be. An editor will eventually review the note and your quiz, but there's no reason for it to go offline in the meantime.
If your quiz is archived and you receive a correction note, then you can't make changes, but an editor can. Indicate in the text box attached to the correction note exactly what corrections need to be made (please be as specific as possible!) and an editor will review the note and make the changes.
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Just because there's twilight doesn't mean we can't tell the difference between night and day