If the ONLY pollutants found in the atmosphere over a city are oxides of nitrogen, suspended lead compounds. carbon monoxide and high levels of methane, the probable source(s) of the pollution must be?
-
A.
automobile exhaust and biological decomposition -
B.
combustion of coal and automobile exhaust -
C.
biological decomposition only -
D.
combustion of coal, automobile exhaust and biological decomposition -
E.
combustion of coal and biological decomposition