Which operation may cause the pressure in an inert tank to fall below the prescribed limits（）.

A.A centerline crane can never be operated in tandem
B.One crane is able to work one end of two adjacent hatches
C.These cranes are more economical and weigh less than outboard-mounted cranes
D.One crane is able to work both sides of the ship

A.The cranes may be operated independently
B.The cranes may be interconnected for twin operation
C.When twinned，the crane rotation on the foundation assembly is unlimited
D.All of the above