Often, when he _________ something that ___________ him, he wasted his time drawing some little

pictures. [ ]

A. should be doing; gave

B. should have been doing; was given

C. should do; was given

D. should have been doing; had given

影响商品价格的因素是多方面的，如商品本身的成本、商品的运输和储藏成本、商品的质量和用途，还同生产商的优质服务、市场上同类商品的数量甚至和商品生产者的教育成本有关。

根据这段话，商品价格和以下哪一项无关：

A．商品的成本
B．生产商的优质服务
C．商品的使用说明
D．商品生产者的教育成本