The correct option is C Air pollutant released from oil refinery of Mathura
The Mathura Oil Refinery discharges, nearly 100 tonnes of carbon-monoxide, 60 tonnes of sulfur dioxide, 50 tonnes of hydrocarbons, 4 tonnes of oxides of nitrogen, 3 tonnes of sulfur trioxide, 2 tonnes of aerosols and 10 tonnes of particulates into the atmosphere everyday. Most of these gaseous pollutants will get converted into acids and travel towards Agra for most of the time and cause serious air pollution problems which result in slow but sure discolouration and decay of most of the historical monuments in the region.