Answer:
b. Quartz-rich
Explanation:
In this map of Waldron, we appreciate ridges and valleys. We also know that the bedrock of the region is composed of mudstone and quartz-rich sandstone. The ridges are the ones that compose mountains, such as the Ouachita Mountains. The reason why these mountains are able to be created is because the bedrock is resistant to erosion. Mudstone is easily eroded, but quartz-rich sandstone is more resistant and thus can better stand erosion. Therefore, the bedrock that makes up the ridges is likely to be composed of quartz-rich sandstone.
