The most accurate response regarding the impact of NAFTA on Mexican corn farmers is:
Mexican farmers could not compete with government-subsidized U.S. corn.
NAFTA, implemented in 1994, effectively reduced trade barriers between the U.S., Canada, and Mexico. While it aimed to create an open market and promote economic growth, it had significant detrimental effects on the agricultural sector in Mexico, particularly for corn farmers. U.S. corn farmers benefited from substantial government subsidies, allowing them to sell corn at lower prices. As a result, Mexican farmers faced intense competition from cheaper, subsidized U.S. corn, which made it difficult for them to sell their own produce at viable prices.
The other responses are less accurate. While there were shifts in consumer preferences and some processing jobs left Mexico, the critical factor in the decline of livelihoods for many Mexican corn farmers was the inability to compete with the prices of heavily subsidized U.S. corn. Additionally, flooded markets due to subsidies do not fit the nature of the problem which primarily stemmed from direct competition rather than oversupply from subsidies.