You are presented with the quiz "When does macroevolution over eras occur?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "macroevolution is evolution over geologic time above the level of the species" and "geologists break time down into geologic time units called eras ". 

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


 

     over eras of time      