Fact 1: Skin is used for protecting the body from harmful substances.

Fact 2: Acids are harmful to tissue.

Given the two facts above, answer the question "What is used to protect the body from acid?" with the following options: 
- the skin
 - tube
 - evaporation
 - a tongue
 - electricity
 - fur and fat
 - the bones
 - the mouth


 

 the skin        