Answer:
A century.
Explanation:
I say a century because we can automatically knock out forever and a millennia because resources can not last forever and 1000 years (a millennia) just isn't reasonable.
10 years is just too short, even with the current consumption per year
If I'm wrong then it would be 10 years. Around 50 years would be the most correct answer but you don't have that choice.
Good luck!
