What is it called when softer rocks wear away and leave harder rocks behind?
a. abrasion
c. differential weathering
b. oxidation
d. acidic weathering

The answer is differential weathering. Differential weathering is the process where softer, weaker rocks wear away before harder, more resistant rocks. There are plenty of things that cause rocks to become softer or less weather-resistant. Other factors that also affect the rate of differential weathering are: size, climate, and temperature. 

Answer:   [b]:   "cultural" .