Global warming is the long-term heating of Earth's climate system observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth's atmosphere
Answer:
1-chlorobutane
Explanation:
Given that :
-- The compound A is made to react with alcoholic KOH and produce compound B.
-- The compound B on Ozonolysis produces methanol as well as propanol
The compound A should be a haloalkanes as treatment of haloalkanes with the alcoholic KOH, it will give alkene.

So, the compound B should be Butene
Now the ozonolysis of the compound B or butene will give methanol and propanal as shown :

Therefore, the compound A is 1-chlorobutane.
A. By gaining one or more electrons