The correct answer is option 1, Montreal. The first protocol to ban the emissions of chlorofluorocarbons (CFCs) in the atmosphere was made in Montreal. CFCs are harmful chemicals that contribute to the depletion of the ozone layer. The protocol, known as the Montreal Protocol on Substances that Deplete the Ozone Layer, was signed on September 16, 1987. It was a result of international efforts to address the growing concerns about the thinning of the ozone layer and its impact on the environment and human health. The protocol aimed to reduce and eventually eliminate the production and use of CFCs and other ozone-depleting substances. Since its implementation, the Montreal Protocol has been successful in significantly reducing the global production and consumption of these harmful chemicals.