You are presented with the quiz "What is one thing that rings can tell you?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "the number of rings in a tree trunk can be used to estimate the age of the tree" and "age of young trees is estimated from both trunk circumference and tree height". 

So, what's the best answer to the question?


 

     age of a tree      