Portable fire extinguishers must be provided for the cargo tank area of an unmanned tank barge（）.

A.only when fully loaded

B.if one or more tanks are full

C.when transferring cargo

D.only when the barge is being towed

亨利·明兹伯格在以下哪一个管理领域也做出了巨大贡献（）

A.人力资源

B.市场营销

C.战略管理

D.生产管理