Answer: A) cave formation rates
Step-by-step explanation:
The carbon dioxide in the earth atmosphere is being increasing due to the human activities such as deforestation, and burning of the fossil fuels. The carbon dioxide in the air get mixed with the rain water which seeps into the soil. It results in the accumulation of carbonates in the soil in the form of limestone. The cave of limestone is formed by the groundwater because limestone is a soft material which get easily dissolves in the water.