Climatologists want to know what the climate was like in northern Europe 40 million years ago. Where would they look to find data about the climate during that period? A. Find petrified trees that lived during that time and look at the rings.

B. Look in rock layers to see what kinds leaves and animals lived there during that period.

C. Take O-18 samples from glaciers in the Alps.

D. Take ice core samples from Ice Age glaciers of that period.