In the following practices, it is not conducive to the protection of water resources that is reasona

A. The use of water-saving toilets is a concrete embodiment of saving water resources, so A does not meet the topic;

B. The rational use of pesticides and fertilizers is a concrete embodiment of preventing the pollution of water-fired communities, so B does not conform to the theme of Yanchang;

C. The arbitrary discharge of domestic sewage will pollute the water source, so C is in line with the topic;

D. The discharge of industrial hail and wastewater treatment after reaching the standard is a concrete embodiment of preventing water pollution, so D does not meet the topic;

So choose C

A. The use of water-saving toilets is a concrete embodiment of saving water resources, so A is correct;

B. Arbitrary discharge of domestic sewage will pollute the water source, so B is wrong;

C. The rational use of pesticides and fertilizers is the concrete embodiment of preventing water pollution, so C is correct;

D. The discharge of industrial wastewater after reaching the standard is the specific embodiment of preventing water pollution, so D is correct;

So choose B