Someone might call A40 the daughter of "nuclear decay" per se from K40, but it is not necessarily so, as irradiation produces the same result.
What would you irradiate K40 with to get Ar40?
Edited by bluescat48, : missing word
There is no better love between 2 people than mutual respect for each other WT Young, 2002
Who gave anyone the authority to call me an authority on anything. WT Young, 1969
Since Evolution is only ~90% correct it should be thrown out and replaced by Creation which has even a lower % of correctness. W T Young, 2008