Final answer:
The most significant daily temperature change in rock weathering occurs in midlatitude valleys, where rocks experience hot daytime temperatures and much cooler nighttime temperatures.
Step-by-step explanation:
The most significant daily temperature change in rock weathering occurs in E) midlatitude valleys. Midlatitude valleys experience a wide range of temperatures throughout the day, with hot daytime temperatures and much cooler nighttime temperatures. These temperature fluctuations can cause rocks to expand and contract, leading to mechanical weathering.