Sometimes when you are writing a quiz question, you might decide this is a good question to save into a specific question bank. Even if the question is from a question bank, you might notice a mistake in a question and you want to save the corrected version to the original question bank.
Right now, the only way to do this right now is to copy and paste it all the questions and answers. This is tedious -- especially for multiple choice questions. It would be much easier if there was a save to question bank option.