_________you become a member, you can borrow at the lowest rate

_________you become a member, you can borrow at the lowest rate available anywhere today —13% annually.
A、Unless
B、Once
C、Although
D、While
【正确答案】：B
【题目解析】：Unless意为“除非，如果不”；Once意为“一旦”；Although意为“虽然”；While意为“当......时，然而”；根据句意一旦你成为会员，你就可以以现在任何地方都能获得的最低利率贷款——每年13%，故选B。