Choose the One Alternative That Best Completes the Statement or Answers

Multiple Choice

Choose the one alternative that best completes the statement or answers the question.
-How long will it take a sample of radioactive substance to decay to half of its original amount, if it to the nearest hundredth year.

A) $67.60 \mathrm { yr }$
B) $4.10 \mathrm { yr }$
C) $35.45 \mathrm { yr }$
D) $39.55 \mathrm { yr }$