Emphasis has to be laid on the point（ ）shipment must be made wit

Emphasis has to be laid on the point（ ）shipment must be made within the validity of the L/C.
A、which
B、that
C、what
D、while
【正确答案】：B
【题目解析】：必须强调的重点是装运必须在信用证的有效期内进行。从句中不缺少任何成分，故可排除选项A和C，while意为“然而，当....时”，与句意不符，故选B。