Answer:
The right approach will be "40K".
Step-by-step explanation:
- Radioactive decay seems to be a natural phenomenon at either the scale of individual atoms and something tough to guess whenever a smaller population will decompose, however according to quantum mechanics.
- The 40K decay throughout the globe's crust currently ranks, within a week of 232Th as well as 238U, as either the radioactive isotopes heating element. Quite potentially the component requires radiogenic components, but what is unknown.