Which statement about the rock layers in this illustration must be true?

A.
Erosion occurred between layers F and G.

B.
Layers G, H, and I are the oldest of these rock layers.

C.
Layers B, C, or D contain no fossils.

D.
Layer G is made of sedimentary rock.

Question

Which statement about the rock layers in this illustration must be true?
  

 
 A.
Erosion occurred between layers F and G.
 
 B.
Layers G, H, and I are the oldest of these rock layers.
 
 C.
Layers B, C, or D contain no fossils.
 
 D.
Layer G is made of sedimentary rock.

anonymous · Answer

what do the rock layers look like?
If F and G are thinner, there has been erosion.
If G,H, and I are at the bottom, they are the oldest.
BC and D have to be completely smooth to have no fossils
and G is made of sedimentary rock only if none of the others are true.
I hope this helps...