_{An Isotope of Tc Having a Half-Life of 6}

Multiple Choice

_{An isotope of Tc having a half-life of 6.0 h is used in bone scans.If a certain amount of this Tc is injected into the body,how long does it take for its initial decay rate to decrease BY 99%?}

A) _{0.060 h}
B) _{3.3 h}
C) _{33 h}
D) _{40 h}
E) _{slightly more than a month}