The development of inland waterways is not dependent on _____.

Rivers, canals, lakes and coastal areas have been important waterways since time immemorial. Boats and steamers are used as means of transport for cargo and passengers. The development of inland waterways is dependent on the navigability width and depth of the channel (A), continuity in the water flow (B), and transport technology in use (D)

The average income of people in the area (C) is not directly related to the development of inland waterways.