对于上级公安机关的重要部署及执行有重大社会影响的任务，要在党委的密切领导下进行．( )

The equipment required to remove an on-deck oil spill on a barge transfering oil must either be arried on board or（）.

A.on a tug standing by

B.available by contract with the shore facility

C.kept at the shoreside hose connection during transfer

D.kept in a protected shoreside location readily accessible