Subject :NSO Class : Class 5
The table below shows the different levels of clarity (how easily we can see through) of the air in an area over a year.
Jan - Mar Very Clear
Apr - Aug Moderately
Sep - Dec Very Clear
Which of the following can be the reason(s) for the changes during the period of May - July?
(A) A volcanic eruption
(B) Set up of an industrial factory
(C) A period of drought
(D) Both (A) and (B)