Answer:
Radiocarbon dating
Explanation:
Radiocarbon dating measures radioactive isotopes in once-living organic material instead of rock, using the decay of carbon-14 to nitrogen-14. Because of the fairly fast decay rate of carbon-14, it can only be used on material up to about 60,000 years old.
D.) Is the most sensible answer.
Explanation: I used the process of elimination to solve this. Groundwater recharge sounds too far off of the topic, snow melt is...well...melting snow, infiltration also has nothing to do with the subject, but surface runoff is the only one that makes sense, is on topic, and seems to have a meaning similar to the occurrences describes in your question.
Coal. -from my dad lol ill check
The compound formed by carbon would be very stable and need more energy to break than the sodium compound....