Aztecs built chinampas ('floating gardens') in order to provide additional farm lands (answer C). The idea was to grow crops in small rectangular areas (ci. 30 x 2.5 m) on shallow lake beds. Aztecs began to use chinampas in Tenochtitlan in about 1250 AD.
so a lot of immigrants came to America trying to find greater economic opportunity, and some (aka Pilgrims) arrived in search of religious freedom.
and during the second wave many irish and norwegians emigrated. hope this helped <3
