Study the given Venn diagram and identify the gases (L, M and N) present in our atmosphere.Select the incorrect option regarding characteristics X, Y and Z of these gases.    

L, M and N are oxygen (21%), nitrogen (78%), and carbon dioxide (0.03%), respectively. Oxygen and carbon dioxide gases support life on Earth (X). Oxygen is required by all living organisms for breathing. CO2 is used by green plants for manufacture of food that is directly or indirectly used by different animals to stay alive. CO2, is also a green- house gas that prevents heat from escaping Earth's surface and keeps the temperature of Earth hospitable. Both nitrogen and carbon dioxide gases do not support combustion (V). Oxides of nitrogen react with water vapour present in air to form nitric acid which fall down with rain on Earth's surface as acid rain (Z).