Percentage of americans aged 65 and older
in 1900 = 4%
in 1950 = 8.2%
in 2000 = 12.4%
in 2050 = 20.2%
based on this information, what is happening to the u. s. population?
a. life expectancy is increasing.
b. the population is increasing.
c. average income is decreasing.
d. the poverty level is decreasing.

The correct answer is A. It is not the "population" which is increasing, as it is never stated in this sentence that there are more people in America. It is only said that more and more people get to live longer, where in the 1900 there was only 4%, in 30 years' time there will be 20%. "Income" and "poverty" aren't mentioned anywhere. 

Maybe littering, cutting down trees and pollution