anatomical comparison gene sequencing radiometric analysis fossil depth measurement
I gave my students this multiple choice question: A certain fossil (Y) is found in a layer of rock that lies between two index fossils, X and Z. Surprisingly, the older of the index fossils (Z) is found above the other fossils, suggesting that the rock layer has overturned. Which dating method is best to confirm the rock layer has overturned by determining the ages of these fossils?

Only one answer is correct among these 4 choices:
- anatomical comparison
- gene sequencing
- radiometric analysis
- fossil depth measurement

Could you tell me which one is correct?

radiometric analysis