Which one of the following statements in not correct related to tides?

(a) Gulf with narrow fronts and wider rears experience high tides

(b) The tidal nature of the mouth of the river Hooghly is of crucial importance to Kolkata as port.

(c) Tidal currents take place when a gulf is connected with the open sea by a narrow channel

(d) Tidal bore occurs when a tide enters the narrow and shallow estuary of a river.