What is（are） standard operating procedure（s） used on a Ro-Ro vessel？

What is（are） standard operating procedure（s） used on a Ro-Ro vessel？
A.Periodic inspection and re-tensioning of lashing as required during voyage
B.Lashing may be completed after the vessel leaves port
C.One QMED assigned to oversee the initial loading and lashing
D.All of the above
正确答案：Periodic inspection and re-tensioning of lashing as required during voyage