What is the primary rock type involved in karst topography formation?

Karst topography is primarily formed in areas rich in limestone. This rock type is characterized by its solubility in weakly acidic water, which allows for the development of unique geological features such as caves, sinkholes, and underground rivers. Over time, the chemical weathering process dissolves the limestone, leading to the characteristic rugged terrain associated with karst landscapes.

In regions where limestone is present, the interaction of water with the rock creates a variety of features, including stalactites and stalagmites found within caves. This process is a crucial aspect of understanding not only the formation of karst topography but also the ecosystems that develop within these environments. Thus, limestone is the primary rock type associated with karst topography, making it the correct answer in this context.