Concept:The Montreal Protocol is a global environmental treaty focused on safeguarding the Earth's ozone layer.
Explanation:The main purpose of the Montreal Protocol is to protect the ozone layer, which shields life from harmful ultraviolet radiation.
It was adopted on September 16, 1987, and regulates the production and use of substances that deplete ozone, such as chlorofluorocarbons (CFCs).
Initially signed by 46 countries, it now has nearly 200 signatories, making it one of the most widely supported environmental agreements.
By phasing out ozone-depleting chemicals, the protocol has successfully helped in the recovery of the ozone layer.
Answer:A. Protection of the Ozone layer