It shouldn't be accepted, no matter what the question was. If it said to translate the sentence it isn't correct because montre isn't plural. If it said to type what you heard, it isn't correct because, while "montre" and "montres" sound the same, if it was plural it would be "VOS montres" which does not sound the same as "VOTRE montre". " vos" is pronounced like "voe" with (roughly) the same o sound as in "toe", "doe" and "go". Hope that helps.