Fact 1: Loud noises can cause animals to startle.

Fact 2: Flat spots on rail car wheels cause a loud banging noise.

Given the two facts above, answer the question "Flat spots on rail car wheels can cause what to startle?" with the following options: 
- animals
 - water
 - planes
 - vehicles
 - people
 - nerves
 - deaf people
 - an object


 

 animals        