You are presented with the question "What can a certain protein affect in meat?" and the following answer choices: 
- health
 - piousness
 - stamina
 - retina
 - toughness
 - liveliness
 - saltiness
 - Energy

Now knowing that cartilage is a tough tissue that contains a protein called collagen and collagen contributes to meat toughness, choose the best answer.


 

     toughness    