The Typical Ecological Footprint for a Person in the United

Multiple Choice

The typical ecological footprint for a person in the United States is 8 global hectares (gha) . How would you estimate the number of Earths required to support the entire population of the United States?

A) Multiply the typical U.S. ecological footprint by the number of people who live there, and divide by the total global hectares of biologically productive land.
B) Multiply the typical U.S. ecological footprint by the effective population size of the United States, and divide by the total global hectares of biologically productive land.
C) Take the difference between the typical U.S. ecological footprint and the 1.7 gha sustainable ecological footprint, and multiply this difference by the number of people who live in the United States.
D) Take the difference between the typical U.S. ecological footprint and the 1.7 gha sustainable ecological footprint, and multiply this difference by the total global hectares of biologically productive land.