What common precaution is needed in both drinking and religious use of river water?

Correct answer: Water cleanliness and pollution prevention

Direct answer: A, water cleanliness and pollution prevention. Drinking use requires water that is safe for the body, while religious use also requires people to avoid making the river dirtier and to protect a shared natural resource. The common principle is responsible use: do not add sewage, plastic, flowers wrapped in plastic, chemicals, or other waste; maintain sanitation; and support treatment and clean surroundings. Option A is correct because cleanliness and prevention protect both public health and the river ecosystem. Option B is wrong because dumping more waste makes water unsafe and damages aquatic life. Option C is wrong because blocking the flow can harm habitats, reduce natural movement of water, and create stagnant conditions; it is not a normal precaution for either use. Option D is wrong because cutting banks causes erosion, instability, and habitat damage. Religious importance does not remove the need for hygiene, and drinking importance does not justify wasting or polluting water. Memory cue: “Use respectfully, keep it clean.”