Fact 1: Cartilage is a tough tissue that contains a protein called collagen.

Fact 2: Acid helps dissolve collagen.

Given the two facts above, answer the question "what can acid help dissolve?" with the following options: 
- drink
 - layers of fat
 - an object
 - a solute
 - cartilage
 - Sediment
 - Bodily water
 - roots


 

     cartilage    