What forms the boundary between the North Central Plains and the Coastal Plains? a. Grand Prairie
b. Rolling Plains
c. Caprock Escarpment
d. Balcones Escarpment

The answer is C.

Along the south is another river, the Colorado River, which stretches from the Gulf of Mexico to northern New Mexico. In the east lays the Coastal Plains, and in the west the *Caprock Escarpment* forms a natural boundary between the North Central Plains and the Great Plains.

Hope this helps.