Question

a geologist finds four layers of sedimentary rock. she determines that no geologic events have shifted the layers. she labels the layers a, b, c, and d from the top to the bottom. which statement about these layers is accurate? a is older than b b is older than c. c is younger than a. b is younger than d.

Explanation:

In undisturbed sedimentary rock layers, the lower layers are older. Layers are labeled A (top), B, C, D (bottom). So, upper - layer B is younger than lower - layer D.

Answer:

D. B is younger than D.