What Statement Concerning the Half-Life of a Radioactive Isotope Is

What statement concerning the half-life of a radioactive isotope is FALSE?

A) The half-life of a radioactive isotope is the amount of time it takes for one half of the sample to undergo radioactive decay.
B) The stability of a radioactive isotope is indicated by its half-life; isotopes with shorter half-lives are very unstable.
C) A radioactive isotope with a short half-life emits its radiation quickly.
D) The half-life of a particular radioactive isotope decreases as the amount of the radioactive material decreases.
E) Different radioactive isotopes have different decay rates,and therefore have different half-lives.