问题：

[单选] When lowering manropes alongside a stage rigged over the side of a vessel，they should be allowed to trail in the water（）.

A . to easily remove the kinks that form in the lines
B . to allow the seamen on the stage to know the direction and strength of the current
C . to provide the seaman something to hold onto if he or she falls from the stage into the water
D . only for short periods of time since they will become waterlogged and be very heavy to pull u