16、（）為確保銀行債權，信用狀所要求提示之提單，下列敘述以何者較為妥適？ (A) FULL SET OF CLEAN ON BOARD MARINE BILL OF LADING (B) FULL SET LESS ONE OF CLEAN ON BOARD MARINE BILL OF LADING (C) 2/3 SET OF CLEAN ON BOARD MARINE BILL OF LADING (D) 1/2 SET OF CLEAN ON BOARD MARINE BILL OF LADING