What can be inferred from paragraph 4? ( )

参考解析：

推断题。根据题干定位至第四段。根据选项A关键词3PQ定位至第二句话If this is too much trouble for you, consider appointing a local agent or third-party quality (3PQ) …可知A项表述正确。根据选项B关键词charge可以定位至最后一句话Most agents usually charge by commission from the amount of goods you import佣金是根据进口货物的总量决定，所以选项B表述错误；根据选项C关键词inspect the factory定位至第二句…consider appointing a local agent or third-party quality (3PQ) firm to inspect the factory on your behalf.表明可以雇佣代理商或第三方质检，不一定要个人亲自去，所以选项C表述错误；D选项：参观工厂需要事先预约申请，这句话无法从第四段推断出来。故本题正确答案选A。