It Is Found by the Radioactive Age-Dating Technique That Only

Multiple Choice

It is found by the radioactive age-dating technique that only one-quarter of the original sample of a radiogenic element remains, so the time is calculated to be two half-lives. What does this time represent?

A) the age of the universe
B) the age of the solar system
C) the time since the formation of the elements
D) the time since the rock was formed