Nitrogen compounds 4. Sulphur compounds How many of the above are products of volcanic eruptions?

Answer: D. All four items are products of volcanic eruptions. Volcanic eruptions release a mix of gases and particulates: water vapour (largest fraction, ~60-70%), carbon dioxide, nitrogen compounds (NOx, N2, NH3 in trace amounts), and sulphur compounds (SO2 and H2S — major contributors to acid rain and stratospheric aerosols). All four categories are well-documented volcanic emissions. Sulphur dioxide in particular is the one that drives global cooling after large eruptions (e.g. Mt Pinatubo 1991). Source: NCERT Class 11 Fundamentals of Physical Geography + USGS volcanology references.