Question

Mexico City's most pressing environmental issue is

Answer 1

Mexico City's most pressing environmental issue is  dangerous air pollution. Correct answer: B

In 1992, the United Nations described Mexico City’s air as the most polluted on the planet. Industrial growth, a population boom (from three million in 1950 to some 20 million today), and the proliferation of vehicles are the factors that contributed to the huge air pollution.

Answer 2

 D. Cutting down of the rainforest