the image shows the locations of different fossils in rock layers. which key fossils are older than fossil…

Brief Explanations:

The principle of superposition in geology states that in undisturbed sequences of sedimentary rocks, the oldest layers are at the bottom and the youngest are at the top. Fossils found in lower layers are therefore older than fossils found in upper layers. In the provided image, fossil X is located in the middle rock layer. Fossils B and D are located in the bottom rock layer, which is below the layer containing fossil X. Therefore, fossils B and D are older than fossil X. Fossils A and E are in the top layer, making them younger than X. Fossils C and Y are in the same layer as X, suggesting they are of similar age.

Answer:

Fossil B Fossil D