A certain radioactive element disintegration with a decay constant of `7.9 xx 10^(-10)` sec. At a given instant of time, if the activity of the sample is equal to `55.3 xx 10^(11)` disintegration/sec, then number of nuclei at that instant of time.

Options

A. `7.0 xx 10^(21)`
B. `4.27 xx 10^(13)`
C. `4.27 xx 10^(3)`
D. `6 xx 10^(23)`

Answer

A