International Day for the preservation of the Ozone layer is observed on ______.

September 16

The correct answer is Option (3) - September 16

The International Day for the Preservation of the Ozone Layer is observed on September 16 each year. This day commemorates the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987, which is aimed at phasing out the production and use of ozone-depleting substances to protect the Earth's ozone layer.