Fact 1: Wind and rain cause erosion.

Fact 2: Some mountains are caused by erosion.

Given the two facts above, answer the question "What are some mountains caused by?" with the following options: 
- Physical weathering
 - saucers
 - ice wedging
 - alluvial
 - animals
 - detritus
 - aliens
 - Wind and rain


 

        Wind and rain 