In the formula Aſt) = Apekt, A is the amount of radioactive material remaining from an initial amount Ao at a given time t, and k is a negative constant determined by the
nature of the material. A certain radioactive isotope decays at a rate of 0.3%
annually. Determine the half-life of this isotope, to the nearest year.
OA) 100 yr
B) 167 yr
OC) 231 yr
OD 2 yr