Final answer:
Rainwater is slightly acidic due to dissolved CO2 and can form carbonic acid when in contact with limestone. Limestone-rich environments are less affected by acid rain since limestone acts as a buffer, but can still suffer damage over time with continuous exposure. Therefore, the correct option is D.
Step-by-step explanation:
Among the answer choices given, rain water is slightly acidic and when it comes into contact with limestone, it creates carbonic acid. This happens because rainwater is naturally saturated with carbon dioxide from the atmosphere. When this carbon dioxide dissolves in rainwater, it forms carbonic acid, a weak acid that can react with limestone, which is composed of calcium carbonate (CaCO3).
An environment rich in limestone would actually be less affected by acid rain compared to an environment poor in limestone. This is because limestone can act as a buffer against the acidity. When sulfuric acid, a component of acid rain, reacts with limestone, the resulting reaction produces calcium sulfate, water, and carbon dioxide, neutralizing the acid and mitigating its potential to cause damage. However, over time, continuous exposure to acid rain can lead to erosion and degradation of limestone structures.