Which statement is accurate about radioactive dating techniques?

Which statement is accurate about radioactive dating techniques?
1. They use a technique in which the degree of radioactive decay is measured, with younger rocks exhibiting radioactive decay.
2. It does not work well with fossil remains that have not absorbed radiation because scientists cannot measure the radiation with any degree of certainty.
3. They give exact ages of rock strata.
4. They give relative ages of rock strata.
5. They use a technique in which the degree of radioactive decay is measured, with older rock exhibiting radioactive decay.