Question

when did the green revolution happen?
1850-1870
1990-2010
1950-1970

Explanation:

The Green Revolution, which involved the adoption of new agricultural technologies to increase food production, primarily occurred between 1950 and 1970. The other time periods (1850 - 1870 and 1990 - 2010) do not align with the historical timeline of the Green Revolution.

Answer:

1950 - 1970