What can happen if rocks are not weathered in the context of the movement of Earth's materials?

The correct option is: Erosion would be insignificant.

Step 1: Understanding Weathering and Erosion
Weathering is the mechanical breakdown and chemical alteration of rocks at or near the Earth's surface into smaller fragments, sediments, and soil components. Erosion, on the other hand, is the process by which these weathered particles and rock debris are transported from one location to another by natural agents such as water, wind, ice, or gravity.

Step 2: Analyzing the Relationship
Weathering acts as a primary prerequisite for significant erosion. Without weathering to break down solid, unyielding bedrock into loose soil, sand, and smaller rock fragments, erosion agents (such as flowing rivers or wind) would have very little loose material to pick up and move across Earth's surface.

Step 3: Conclusion
If rocks are not weathered, solid rock structures remain intact and resistant to transport. Consequently, the movement of surface materials through erosion would be reduced to negligible or insignificant amounts.