Final answer:
Relative dating involves determining the geological ages of fossils, while absolute dating provides a numerical age.
Step-by-step explanation:
Relative dating is one of the general approaches used by scientists to approximate when an organism lived. It involves determining the geological ages of fossils by comparing their positions in different rock layers or formations. This method does not provide an exact age but gives a relative age of the fossil in relation to other fossils or events.
Absolute dating is another approach used, which involves determining the numerical age of a fossil or rock using methods like radiocarbon dating. This method provides an approximate age of the organism in years.
Therefore, both A and C (Absolute dating and Relative dating) are correct when it comes to scientists approximating when an organism lived.