which fossils shown below are the oldest? * a, b and c b and c c, b and d

which fossils shown below are the oldest? * a, b and c b and c c, b and d
Answer
Brief Explanations:
In geology, the principle of superposition states that in undisturbed sedimentary rock layers, the oldest layers are at the bottom and the youngest are at the top. Fossils found in lower - lying layers are generally older. Fossils B and C are found in the lowest layers across the outcrops shown.
Answer:
B and C