What was observed within a period of 1997 and 2005 in Delhi as regards to air quality ? (a) There was net increase in all the types of air pollutants. (b) Delhi became totally pollution-free during this period only.(c) There was substantial fall in concentrations of CO2 and SO2 . (d) There was decrease in the concentration of H2 S and CO.

What was observed within a period of 1997 and 2005 in Delhi as regards

1.	What was observed within a period of 1997 and 2005 in Delhi as regards to air quality ? (a) There was net increase in all the types of air pollutants. (b) Delhi became totally pollution-free during this period only.(c) There was substantial fall in concentrations of CO2 and SO2 . (d) There was decrease in the concentration of H2 S and CO.
Answer» Correct option is (c) There was substantial fall in concentrations of CO₂ and SO₂.