You are presented with the quiz "Estimating the age of trees can be used for what" 

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 "tree-ring dating the 1700 Cascadia earthquake". 

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


 

   earthquake history        