The explosion of mexico city’s population beginning in the 1960s was the result of: a) municipal annexation. b) increasing birth rates. c) international migration. d)internal migration.

d) Internal migration.

Explanation:

Mexico City had been the ultimate goal for Mexican internal migration, mainly because of the economic opportunities and the developed infrastructure in education, culture, and health. The 1960s saw the greatest increase in the city´s population in its entire history, still, mostly because of in-migration. Nevertheless, the city’s immigration eventually decreased, getting a negative net migration between 1985 and 1990.

i think its provide for the common defense

. political or economical policy that isolates a country from participating in international relationships. it has been suggested that the united states participates in isolationism because of its lack of involvement in particular wars or alliances.