The correct answer is C. Are ozone-depleting substances (ODS)
Explanation:
Chlorofluorocarbons or CFCs are substance containing carbon, chlorine, and fluorine widely used in certain products such as refrigerants and aerosol products, mainly because these substances are safe as they have low toxicity and flammability. However, in the last decades, it was found CFCs contribute to the ozone layer depletion, which means CFCs made the ozone layer thinner and this contributes to the greenhouse effect and many other environmental issues as the ozone layer filters the ultraviolet radiation. Because of this, CFCs are no longer used in many countries, indeed in 1987 and an international treaty was created in which all the countries from the European Union and the United Nations agreed to stop using these products and replacing them by substances that did not contribute to the depletion of the ozone layer. Thus, it can be concluded the use of CFCs have been banned by many countries because these substances are ozone-depleting substances.
