You are presented with the question "Trees have woody stems covered with what?" and the following answer choices: 
- food and shelter
 - smooth ridges
 - looseness
 - protective layer
 - Organic compounds
 - plastic sheet
 - heat energy
 - thin metal

Now knowing that trees have woody stems covered with bark and during the stripping, the protective layer of inner bark is removed, choose the best answer.


 

    protective layer     