In addition to setting the price

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：除了确定产品的价格外，企业还必须决定是否向客户提供特别折扣和信用条款。if意为“如果，是否”，不能用于不定式之前；句中不缺少任何成分，也不是从句，故可排除选项B和C；whether意为“是否”，可用于不定式之前。