Answer:
To find the age of the fossil
Step-by-step explanation:
You measure the intensity of the radiation (counts per minute) from a given mass of the sample.
If you know the half-life of the radioactive isotope (e.g., carbon-14), you can work backwards and calculate the number of years since the organism died.
A is wrong. You use a balance to determine the mass of the fossil.
C is wrong. The level of radiation tells you nothing about the species of the fossil.
D is wrong. You use a radiation detector to determine if a fossil is radioactive.