Explanation:

- Carbon: Carbon itself does not destroy the ozone layer. However, when bonded with other elements, such as fluorine, it forms chlorofluorocarbons (CFCs) that do harm the ozone layer.

- Chlorine: Chlorine from CFCs and other industrial chemicals is responsible for ozone layer depletion. Once released into the atmosphere, chlorine atoms break down ozone molecules.

- Sulphur: Sulphur compounds, such as sulphur dioxide, primarily contribute to acid rain and air pollution, not ozone depletion.

- Silicon: Silicon does not play a direct role in ozone layer depletion.

- Correct Answer: 2, Chlorine