The setting of an outlet is defined as the ratio of the
[A].
rate of change of discharge of an outlet to the rate of change of discharge of the distributing channel
[B].
rate of change of discharge of an outlet to the rate of change in level of the distributing surface, referred to normal depth of the channel
[C].
depth of the sill or the crest level of the module below the full supply of the distributing channel to the full supply depth of the distributing channel