Question

which increases the rate of soil formation?
○ mixed layers
○ more precipitation
○ cooler temperatures
○ very hard parent material

Explanation:

Soil formation rate is driven by factors like climate, parent material, and biotic activity. More precipitation increases chemical weathering (dissolving minerals) and biological activity (plant growth, microbial action), both of which speed up soil development. Cooler temperatures slow chemical reactions and biological activity. Very hard parent material resists weathering, slowing formation. Mixed layers are a result of soil formation, not a driver.

Answer:

more precipitation