Carbon monoxide is a major pollutant of

Which of the following is the largest source of air pollution these days?

Oxides of sulphur and nitrogen are important pollutants of

Consider the following statements about a scrubber:
$I.$ It is used to remove gases like sulphur dioxide from industrial exhaust.
$II.$ In a scrubber,the exhaust is passed through a spray of water or lime.
$III.$ Water dissolves gases and lime reacts with sulphur dioxide to form a precipitate of calcium sulphate or calcium sulphide.
Which of the statements given above are correct?

For the control of air pollution in Delhi, all buses of Delhi were converted to run on $A$ by the end of $B$ as per the directives of the $C$. Complete the given statement by choosing appropriate options for $A-C$.

Select the correct option based on the given diagram.