A radioactive sample of 141Cs has a half-life of 32.5 days. In a sample that contains 8.00*10^7 nuclei of 141Cs, how many beta particles per second will be emitted?

A 19.8
B 1.7*10^6
C 71 076
D 1185
E 2.47*10^-7

The 141 supposed to be a superscript text, but firefox won't let me type it as such. It represents an isotope of cesium.