Temperature shifts can trend toward warming or cooling, based on a number of gravitational, seasonal, and human variables. These variables affect different ecosystems differently and thus should produce a random pattern in which some ecosystems warm while others cool. However, data gathered in a 1980s study shows that the shifts occur in a definitely skewed pattern, with most areas’ temperatures rising simultaneously.
We have to explain the paradox that various variables affect ecosystems differently and thus produce random pattern of warm and cool climate over these ecosystems. However data from 1980 shows that temperature increased in skewed pattern in different ecosystems
A Massive warming can result from widespread pollution in many countries.- External variable which explains the paradox, keep it.
B Certain regions with specific geographical features respond in varying degrees to surrounding changes.- Doesn't resolve the paradox as it mentions the effect of surroundings on the geographical regions with their specific features but we have to explain the reverse. Discard it.
C Some regions grow warmer due to increased volcanic activity in those regions.- For some region temperature increase is there due to volcanic eruption but the statement that conditions are skewed over different ecosystems is still not resolved. Most ecosystem don't have volcanic eruption so why are conditions skewed there as well.
D In the 1990s and beyond, which were not as well documented, human pollution skewed the trend toward warming.- premise discuss about data collected in 1980 but the option discuss about 1990 and that too undocumented, however at first go option seems similar to A but can be discarded as paradox is not resolved regarding the data collected in 1980.
E Regions that are geographically closest are most likely to be affected in similar ways.- This also seems a contender to resolve the paradox but the original statement mentions that various ecosystems shows random pattern depending upon various variables.
Therefore A is the correct answer
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