The bargain they reached with their employers was to reduce their wage demand and accept a shorter

working week______.[ ]

A. in return

B. in all

C. in reality

D. in turn

某服装厂与某纺织厂签订了一份购销合同，约定纺织厂向服装厂供给纯毛衣料100万米，按纺织厂提供的样品交货，纺织厂交货经服装厂验收后，服装厂即将衣料加工成衣服销售。后购买衣服的消费者反映衣料的质量有问题。经过检验，纺织厂提供的样品是含有8%涤纶的衣料，纺织厂亦是按该样品向服装厂交货的。本案的性质应如何认定 ( )

A．重大误解

B．民事欺诈

C．违约行为

D．侵权行为