Explanation:
The answer is A, Buddisum
Sinkholes and karst topography are a clear indication that the groundwater is moving through a limestone and forming caves that periodically collapse.
1. As climate changes (gets cooler or warmer), then that relates to the amount of arable land, crops and animals to feed off of.
2. The characteristics of civilization are: social structure, stable food supply, religion, government, writing, culture and technology.