52. In which year was the first world environment day observed? A.1973 B.1972 C.1980 D.1974
Option D Solution: The day was first observed in 1974 in the city of Spokane in the USA. In 1972, the United Nations General Assembly established the World Environment Day on the first day of the Stockholm Conference on the Human Environment. Two years later, in 1974 the first WED was held with the theme "Only One Earth".
