Which increase the rate of soil formation? check all that apply. a. mixed layers b. large grain sizes c. more precipitation d. warmer temperatures e. very hard parent material

Option C and D

Explanation:

The five major factors that play a vital role in increasing or decreasing the rate of soil formation

The less hard a parent materials, the easy it is to break it down into small pieces and convert it into soil. The harder the parent soil is , the more time it will take to break.

Climate - warm and wet climate helps in disintegrating rocks faster.

Hence, only option C and D are correct