In addition to setting the price of a product, business firms must decide（ ）to offer special discount and credit terms to their customers.
A、if
B、which
C、whatever
D、whether
【正确答案】：D
【题目解析】：句意：除了设置一个产品的价格,企业还必须决定是否向消费者提供折扣及信用条款。whether可以引导带to的不定式，if则不能。
