The Black Death was a plague that killed nearly 50% of people. One of the long term effects was people's viewpoint on religion. Many people who saw the death affecting everyone and thought it was the hand of God stopped believing in God. This could have spurred the Renaissance/Enlightenment thinkers who focused on humanism and secularism. They such as John Locke believed reason was the most important, not faith. It also broke the Church's absolute power. Many of the churches who were the only place for refuge and those who went to administer last rights then got sick and died as well. Sonce so many people died, there were more jobs open and actually raised the standard of living. Wages rose because there were less people and marked the end of feudalism. It paved the way for the renaissance. It also led to persecution of certain groups such as Jews
I think it is the first one (shoppers find sushi...). Cultural diffusion refers to the spread of different cultures around the world. Finding Asian food in America definitely shows an example of cultural spread.