[单选题]
01.17: If 25% of a sample of a radioactive isotope decays in 4 h ot)xy)p5f: elrne2k;our vcnp 5 sn f3( p :nn*9ygcx;34gyvn-d(l6czmts, we would estimate the sample's half life to 5dn3ty- p(m9zvv yp ;cl( ngn 4gcf6s*3:cnxnbe about
A. 1.9 hours
B. 4.0 hours
C. 8.0 hours
D. 9.6 hours
E. 13.8 hours
