Concept:International Ozone Day commemorates the signing of the Montreal Protocol in 1987, which aims to protect the ozone layer.
Explanation:The United Nations General Assembly declared 16 September as the International Day for the Preservation of the Ozone Layer in 1994.
This date marks the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987.
The ozone layer is a natural gas layer in the stratosphere (10–50 km above Earth) that shields us from harmful ultraviolet (UV) radiation.
Ozone depletion is caused by substances like CFCs and HCFCs used in refrigerators, air conditioners, and fire extinguishers.
The depletion is greatest over Antarctica (South Pole).
For board exams, remember the exact date: 16 September.
Answer:A.
16th September