Which one of the following contributes largely to the ‘green house effect’ ?

The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone. When these gases are ranked by their direct contribution to the greenhouse effect in percentage terms, the most important are: Water vapour: 36-72 per cent; Carbon dioxide: 9-26 per cent; Methane: 4-9 per cent; and Ozone: 3-7 per cent.