Correct Option (D)
All four of the listed items are products of volcanic eruptions.
- Pyroclastic debris: This refers to fragmented rock material of various sizes, such as volcanic bombs, lapilli, and ash, that is ejected during explosive volcanic eruptions.
- Ash and dust: Fine particulate matter, including volcanic ash and dust, is a common product of explosive volcanic activity. These particles can be dispersed over vast distances in the atmosphere.
- Nitrogen compounds: Volcanic gases naturally contain nitrogen and various nitrogen compounds, though typically in smaller proportions compared to other major volcanic gases like water vapour and carbon dioxide.
- Sulphur compounds: Volcanoes are significant natural sources of sulphur compounds, primarily sulphur dioxide (SO₂) and hydrogen sulphide (H₂S). These gases contribute to atmospheric aerosols and can lead to phenomena such as acid rain.
Incorrect Options:
Options (1), (2), and (3) are incorrect because they suggest that fewer than all four of the listed items are products of volcanic eruptions. Scientific evidence confirms that pyroclastic debris, ash and dust, nitrogen compounds, and sulphur compounds are all distinct outputs of volcanic activity.