The Isotope Has a Half-Life of 5,715 Years

Multiple Choice

The isotope has a half-life of 5,715 years.After 20,000 years,a sample of the isotope is reduced 0.7 grams.What was the initial size of the sample (in grams) ? How large was the sample after the first 2,000 years? Round your answers to four decimal places. ​

A) 7.9172 g,6.2119 g
B) 10.2924 g,8.0755 g
C) 4.7503 g,3.7271 g
D) 6.3338 g,4.9695 g
E) 3.9586 g,3.1059 g