Final answer:
The Green Revolution was responsible for averting a food crisis in developing countries during the 1970s and 1980s, thanks to agricultural innovations initiated by Norman Borlaug that led to increased food production.
Step-by-step explanation:
The entity largely responsible for preventing a food crisis in developing countries during the 1970s and 1980s was the Green Revolution. This series of innovations in agriculture was spearheaded by Norman Borlaug, who developed high-yield, disease-resistant crops starting in Mexico. The adoption of these high-response varieties of wheat, rice, and other crops, along with expanded irrigation and increased use of artificial fertilizers and pesticides, led to explosive improvements in agricultural yields worldwide.