Carbon-14 is a radioactive isotope that decays exponentially at a rate of 0.0124 percent a year. How many years will it take for carbon-14 to decay to 10 percent of its original amount? The equation for exponential decay is At = A0e⁻rt.
a) 55.85 years
b) 56.73 years
c) 57.61 years
d) 58.49 years