Isotopes A and B have initial masses of 100 g and 80 g, respectively. The half-life of isotope A is 10 days, while the half-life of isotope B is 5 days. Which statement about their masses after 30 days is most accurate?
a) The masses will be equal because 30 days is a common multiple of both half-lives.
b) Isotope B will have the greater mass primarily because its half-life is shorter.
c) Isotope A will have the greater mass primarily because its decay constant is smaller.
d) Isotope B will have the greater mass because its initial mass advantage offsets its faster decay.