How do sinkholes typically form without physical disturbance to the rock?

Sinkholes commonly form through a natural process called subsurface erosion, which is primarily the dissolution of soluble bedrock, such as limestone, by slightly acidic rainwater. Over time, rainwater absorbs carbon dioxide from the atmosphere and soil, forming a mild carbonic acid solution. When this acidic water seeps into the ground, it interacts with the limestone, gradually dissolving it and creating underground voids or cavities.

As these cavities enlarge, they may eventually lead to the collapse of the surface layer, giving rise to a sinkhole. This process does not require any external physical disturbance, such as drilling or seismic activity. Instead, it occurs slowly over time as water continuously erodes the limestone, making option C the most appropriate answer. Understanding this process highlights the importance of geochemical interactions in groundwater systems and their implications for sinkhole formation.