If both water and grass are declining for one-horned rhinoceros in an area, which conclusion is correct?

Correct answer: Habitat quality for rhinoceros is declining

The direct answer is A, habitat quality for rhinoceros is declining. Habitat means the complete living place of an animal, including water, food, vegetation, shelter, and suitable conditions. The one-horned rhinoceros is associated with grasslands, wetlands, marshes, and areas where water and grasses are available. Step by step: water is declining, so drinking and cooling opportunities are reduced; grass is declining, so food is reduced; when important habitat resources decline together, the habitat becomes less suitable; therefore habitat quality is declining. Option A correctly combines these facts. Option B is wrong because a rhinoceros does not need only dry rock; it needs food, water, and suitable vegetation. Option C is wrong because water and grass are essential resources, not irrelevant ones. Option D is wrong because falling resources show that conservation still needs attention, not that it is complete. Exam cue: judge habitat by the resources an animal needs.