Soil forms from the weathering of bedrock. This means that over time, the bedrock on Earth's surface is broken down into smaller pieces through processes like wind, water, and the actions of plants and animals. These broken-down particles mix with organic matter, such as decomposed plants and animals, to create soil. The weathering of bedrock is a critical factor in the formation of soil. Therefore, the correct answer is "Soil forms from the weathering of bedrock."