Answer: Option D.
Earth warming is warming more than previous natural cycles.
Step-by-step explanation:
Global warming or earth warming is the increase in the average temperature of climate system of the earth. This is caused by green house gases, aerosols and soot.
The earth's warming is warming more than the previous natural cycles because of continual increase in global industrial era from land use changes I.e continuos deforestation, pollutions and many more.