单项选择题
A.运输单据B.其他单据C.保险单据D.商业发票
A.L/C BY ACCEPTANCEB.L/C BY PAYMENTC.L/C BY NEGOTIATIOND.L/C BY MIXED PAYMENT
A.进口商；出口商B.开证行；进口商C.出口商；进口商D.出口商；开证行