The Trans-Pecos ecoregion occupies the westernmost portion of Texas. It includes the Chihuahuan Desert, the Guadalupe Mountains, the Davis Mountains, and Big Bend National Park. This ecoregion ranges in elevation from 2,500 ft. to 8,749 ft and receives on average less than 12 inches of rainfall a year, although this varies with elevation. Soils at the lowest elevations in this area are the result of after the erosion of the Guadalupe and Davis Mountains.
(A) disposition
(B) weathering
(C) flash floods
(D) river action

(C) flash floods

Explanation:

There is 12 inches of rainfall so there's gonna be flash floods

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.