单选题 The market for (manufactured goods) is (which) economists call "imperfect," because each company has its own style; and all of the arts of advertisement and salesmanship are devoted (to making) it (even more imperfect) by attracting buyers to particular brand names.
【正确答案】 B
【答案解析】(改为:what)what引导宾语从句,而which引导的是定语从句。