Answer:
D. 200%
Step-by-step explanation:
While Americans constitute the 5% of the world population, they use around the 24% of the world's energy.
Then, if the 100% of the population were like the Americans, we have:
5%*x = 100%
x = 100%/5% = 20
the whole population is 20 times the population of the US, then the total energy used is 20 times the energy used in the US.
Then the energy that the 100% of the population would use is equal to:
20*24% = 480%
So we actually would need like 5 Earths.
The option is 200%