Even though the mayor was not ________the argument for the proposal, she decided to forgo her vote.
句意：尽管市长不是这个提议的理由，她还是决定放弃她的投票。opposed to 反对。influenced by受……影响。in support of支持；拥护。indifferent to无兴趣，不关心。因此，本题的正确答案是D。