The Burden of Human Made Aerosol Sulfate in the Earth's $B ( x , n ) = \frac { x n } { A }$

Multiple Choice

The burden of human made aerosol sulfate in the earth's atmosphere, in grams per square meter, is $B ( x , n ) = \frac { x n } { A }$
Where x is the total weight of aerosol sulfate emitted into the atmosphere per year and n is the number of years it remains in the atmosphere. A is the surface area of the earth, approximately $5 \times 10 ^ { 14 }$ square meters. Calculate the burden given the 1995 estimated values of $x = 2.8 \times 10 ^ { 14 }$ grams per year and $n = 20$ days. Enter the number of grams per square meter as a number without the units. Round to three decimal places.

A) 0.061 grams per square meter
B) 0.098 grams per square meter
C) 0.031 grams per square meter
D) 0.767 grams per square meter
E) 11.200 grams per square meter