We have an answer quota set at one (respondents choose from a drop down list). A respondent started the survey and chose an answer. She did not complete the survey, however, and now the answer has disappeared. If we delete her partial response, will the answer choice show back up in the drop down box?
As a moderator and fellow user of SG I have found the Question Answer Limit Options are somewhat touchy, SG even notes it in the documentation. One important point they bring up in documentation is that these quotas react even for partial completions. So once someone selects that option and moves forward in the survey, it has counted against that number.
Also, my best understanding is that the number is static, so if responses are added or deleted on the backend, it will not affect the quota count.
I personally use this feature often for event sign ups and I have to make sure I stay on top of the Answer Limit Options, so in a case like you have, I would delete the response and then increment the Answer Limit Option by 1. After reading documentation you might notice this is somewhat frowned upon as this is a static value.