Fact 1: Erosion causes a river to become deeper and wider.

Fact 2: Erosion is the work of wind, water, and time.

Given the two facts above, answer the question "The work of what causes a river to become deeper and wider?" with the following options: 
- looseness of dirt or compost
 - just time
 - Veins and arteries.
 - just wind
 - Physical weathering
 - The area was once underwater
 - just water
 - wind, water, and time


 

        wind, water, and time 