The Isotope ${ } ^ { 14 } \mathrm { C }$

Multiple Choice

The isotope ${ } ^ { 14 } \mathrm { C }$ has a half-life of $5.715$ years. After 2,000 years, a sample of the isotope is reduced to $1.2$ grams. What was the initial size of the sample (in grams) ? How much will remain after 20,000 years (i.e., after another 18000 years) ? Round your answers to four decimal places.

A) $1.0706,0.0947$
B) $2.4471,0.2164$
C) $1.5294,0.1352$
D) $2.1412,0.1893$
E) $1.9883,0.1758$