You are presented with the question "what unit of time can be estimated by the rings in a tree trunk?" and the following answer choices: 
- hours
 - decades
 - months
 - H20
 - Joules
 - DNA
 - years
 - seasons

Now knowing that the number of rings in a tree trunk can be used to estimate the age of the tree and age of Pine trees (AGE) in years, choose the best answer.


 

       years  