Rather than spread control among hundreds oreven thousands of local, regional, and nationalagencies that watch various aspects of water use,countries should set up central authorities tocoordinate water policy.In order to raise the efficiency of the water supply,measures should be taken to _______.
A. centralize the management of water resources
B. increase the sense of responsibility of agencies at all levels
C. guarantee full protection of the environment
D. encourage local and regional control of water resources