A limestone bedrock is the most likely natural factor that may support the formation of a sinkhole.
Explanation:
Sinkholes are usually formed when for a prolonged period, water or other erosive substance percolates or seeps through a soluble rock and gradually erodes it in a deep cavity-like formation.
This cavity undergoes erosion and the walls of the cavity keep weathering to form a sinkhole. Impervious non-reactive rocks do not favor the formation of a sinkhole.
