The following graph shows the rates of decay for four parent isotopes. Based on the graph, which parent isotope most likely has a half-life of 4.5 billion years? (2 points) Graph showing the rates of decay for four parent isotopes, labeled A, B, C, and D. After 4.5 billion years, approximately 1 percent of parent isotope A exists; approximately 50 percent of parent isotope B exists; approximately 85 percent of parent isotope C exists; and approximately 95 percent of parent isotope D exists. Public Domain Group of answer choices A B C D