Which of the following is NOT a major greenhouse gas? 

A)  chlorofluorocarbons (CFCs)  
B)  sulphur dioxide 
C)  carbon dioxide and water vapour 
D)  ozone

Chlorofluorocarbons (CFCs), carbon dioxide and water vapour, and ozone are all major greenhouse gases, contributing to the warming of the earth's atmosphere. However, sulfur dioxide is not considered a major greenhouse gas, although it is a primary contributor to air pollution and has other ecological impacts.