The correct answer is - 3. maize.
The maize was the basis of the diet of the civilizations of Mesoamerica. It was one of the first wild plants in which the people from this region saw a potential as a big and stable food source, so they started to farm it. All of the civilizations we know from this region, like the Olmecs, Toltecs, Mayans, Aztecs, formed and developed their civilizations around the food source that was provided by the maize.
