Select the appropriate option regarding the ozone hole.

What was the purpose of the $Montreal$ $Protocol$?

The ozone hole is largest over $.......$.

$A$ decrease in the concentration of which gas in the atmosphere leads to an increase in the incidence of skin cancer?

Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancers?

Recognizing the deleterious effects of ozone depletion,an international treaty was signed at Montreal in $1987$ to control the emission of ozone-depleting substances,which is known as $.........$.