Which option describes how the absolute age of a fossil is commonly determined?
The carbon-14 in a fossil breaks down over time. The remaining amount of carbon-14 in the
fossil can be used to calculate its age.
The carbon-12 in a fossil breaks down over time. The remaining amount of carbon-12 in the
fossil can be used to calculate its age.
Once the organism is dead, carbon-12 starts to accumulate. The existing amount of carbon-12
in the fossil can be used to calculate its age.
Once the organism is dead, carbon-14 starts to accumulate. The existing amount of carbon-14
in the fossil can be used to calculate its age.