Our terms of payment are by irrevocable L/C _________ by draft a

Our terms of payment are by irrevocable L/C _________ by draft at sight.
A、acceptable
B、available
C、paying
D、opening
【正确答案】：B
【题目解析】：irrevocable L/C available by draft at sight不可撤销的即期信用证
句意：我们的付款条件是不可撤销的即期信用证。