体育用品商店有篮球和排球共45个，其中篮球占60%，当卖出一批篮球后，篮球占现存总数的25%，卖出的篮球是______个．

A．(A) We offer a five to ten percent discount unless you require immediate delivery.

B．(B) We promise to refund the money if we cannot send our products in time.

C．(C) If you order our products right now, we will give you certain commission in cash.

D．(D) Buying our products will save not only your money, but also your time.