The correct answer is option 1: Chlorofluorocarbon. Greenhouse gases have the ability to trap heat in the Earth`s atmosphere and contribute to global warming. Chlorofluorocarbons (CFCs) are synthetic compounds that were commonly used in aerosol cans and refrigerants. Despite being phased out due to their harmful effects on the ozone layer, they still have a significant heat-trapping ability. Methane (option 2) is another potent greenhouse gas, but its heat-trapping ability is lower than that of CFCs. Carbon dioxide (option 3) is the most abundant greenhouse gas and plays a major role in climate change, but it has a lower heat-trapping ability compared to CFCs. Nitrous oxide (option 4) is also a potent greenhouse gas, but its heat-trapping ability is lower than that of CFCs.