In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

[Q]: Factories in China often produce what type of gas in their emissions that acts as pollution?, Context: A dense wave of smog began in the Central and Eastern part of China on 2 December 2013 across a distance of around 1,200 kilometres (750 mi), including Tianjin, Hebei, Shandong, Jiangsu, Anhui, Shanghai and Zhejiang. A lack of cold air flow, combined with slow-moving air masses carrying industrial emissions, collected airborne pollutants to form a thick layer of smog over the region. The heavy smog heavily polluted central and southern Jiangsu Province, especially in and around Nanjing, with its AQI pollution Index at "severely polluted" for five straight days and "heavily polluted" for nine. On 3 December 2013, levels of PM2.5 particulate matter average over 943 micrograms per cubic metre, falling to over 338 micrograms per cubic metre on 4 December 2013. Between 3:00 pm, 3 December and 2:00pm, 4 December local time, several expressways from Nanjing to other Jiangsu cities were closed, stranding dozens of passenger buses in Zhongyangmen bus station. From 5 to 6 December, Nanjing issued a red alert for air pollution and closed down all kindergarten through middle schools. Children's Hospital outpatient services increased by 33 percent; general incidence of bronchitis, pneumonia, upper respiratory tract infections significantly increased. The smog dissipated 12 December. Officials blamed the dense pollution on lack of wind, automobile exhaust emissions under low air pressure, and coal-powered district heating system in North China region. Prevailing winds blew low-hanging air masses of factory emissions (mostly SO2) towards China's east coast.
[A]: SO2


[Q]: What country do you think starts with a T ?, Context: The effects of local surface low pressure are extremely limited because upper-level subsidence still continues to block any form of air ascent. Also, to be protected against rain-bearing weather systems by the atmospheric circulation itself, the desert is made even drier by his geographical configuration and location. Indeed, the extreme aridity of the Sahara can't be only explained by the subtropical high pressure. The Atlas Mountains, found in Algeria, Morocco and Tunisia also help to enhance the aridity of the northern part of the desert. These major mountain ranges act as a barrier causing a strong rain shadow effect on the leeward side by dropping much of the humidity brought by atmospheric disturbances along the polar front which affects the surrounding Mediterranean climates.
[A]: Tunisia


[Q]: Who went to school in Chicago?, Context: Hayek had made contact with many at the U. of Chicago in the 1940s, with Hayek's The Road to Serfdom playing a seminal role in transforming how Milton Friedman and others understood how society works. Hayek conducted a number in influential faculty seminars while at the U. of Chicago, and a number of academics worked on research projects sympathetic to some of Hayek's own, such as Aaron Director, who was active in the Chicago School in helping to fund and establish what became the "Law and Society" program in the University of Chicago Law School. Hayek, Frank Knight, Friedman and George Stigler worked together in forming the Mont Pèlerin Society, an international forum for libertarian economists. Hayek and Friedman cooperated in support of the Intercollegiate Society of Individualists, later renamed the Intercollegiate Studies Institute, an American student organisation devoted to libertarian ideas.
[A]:
Hayek, Frank Knight, Friedman and George Stigler


