<P> Los Angeles in particular is strongly predisposed to accumulation of smog, because of peculiarities of its geography and weather patterns . Los Angeles is situated in a flat basin with ocean on one side and mountain ranges on three sides . A nearby cold ocean current depresses surface air temperatures in the area, resulting in an inversion layer: a phenomenon where air temperature increases, instead of decreasing, with altitude, suppressing thermals and restricting vertical convection . All taken together, this results in a relatively thin, enclosed layer of air above the city that cannot easily escape out of the basin and tends to accumulate pollution . </P> <P> Though Los Angeles was one of the best known cities suffering from transportation smog for much of the 20th century, so much so that it was sometimes said that Los Angeles was a synonym for smog, strict regulations by government agencies overseeing this problem, including tight restrictions on allowed emissions levels for all new cars sold in California and mandatory regular emission tests of older vehicles, resulted in significant improvements in air quality . For example, air concentrations of volatile organic compounds declined by a factor of 50 between 1962 and 2012 . Concentrations of air pollutants such as nitrous oxides and ozone declined by 70% to 80% over the same period of time . </P> <Ul> <Li> 1943, July 26, Los Angeles, California: A smog so sudden and severe that "Los Angeles residents believe the Japanese are attacking them with chemical warfare ." </Li> <Li> 1948, October 30--31, Donora, Pennsylvania: 20 died, 600 hospitalized, thousands more stricken . Lawsuits were not settled until 1951 . </Li> <Li> 1966, November 24, New York City, New York: Smog kills at least 169 people . </Li> </Ul> <Li> 1943, July 26, Los Angeles, California: A smog so sudden and severe that "Los Angeles residents believe the Japanese are attacking them with chemical warfare ." </Li>

The photochemical smog in india is maximum in which of the following cities