These shoes are too big .Do you have a smaller-------?

These shoes are too big .Do you have a smaller_______?
A.one B.ones C.pairs D.pair
我认为答案为B，可是报纸上答案为D，这是08年天津大港区中考题
给一个比较详细的原因

D pair 名词 n.
1.一对,一双,(两部分形成的)一件[C][(+of)]
2.一对(夫妻、情侣、舞伴等)[C][G]
That pair are always quarreling.
那对夫妻老是争吵.
不及物动词 vi.
1.成对,配对
Birds often pair for life.
鸟儿常常终生配对.
2.组成一对一对
3.(动物)交配
4.结婚
及物动词 vt.
1.使成对;使成配偶;使交配
They paired John and Mary for the dance.
他们将约翰和玛丽配对成舞伴.
2.把...组成一对一对
3.为...配搭档[(+with)]