_____, the population of China is the largest in the world. [ ]

A. It is known that 　

B. As is well known 　

C. Which is well known 　

D. We all know that

ABC会计师事务所承接了F公司20×8年度财务报表审计业务，己注册会计师任项目负责人。在销售与收款循环业务审计中，遇到了下列事项，请代为做出正确的专业判断。

下列职责分工中，你认为有缺陷的有( )。

A．会计人员A负责登记应收账款明细账与应收账款总账

B．销售人员B负责同客户谈判销售价格、信用政策、发货并签订合同

C．销售人员C根据B与客户商谈的销售条款签订合同，并负责收取销售现款

D．销售人员D根据C与客户签订的协议负责向客户发货，并负责开具销售发票