Flexibility of an outlet may be defined as the ratio of the rate of change of :
a) Outlet discharge to the rate of change of water level of the parent channel
b) Outlet discharge to the rate of change of the discharge of the parent channel
c) Parent channel discharge to the rate of the change of the outlet discharge
d) Parent channel water level to the rate of the outlet discharge
a) Outlet discharge to the rate of change of water level of the parent channel
b) Outlet discharge to the rate of change of the discharge of the parent channel
c) Parent channel discharge to the rate of the change of the outlet discharge
d) Parent channel water level to the rate of the outlet discharge