Answer:
Right choice is:
c. Elements of a nation or people's culture get transformed or more fully embraced elsewhere before being re-imported into the culture of origin.
Explanation:
The "pizza effect" refers to the fact that pizza , which is an original Italian dish, was taken to the USA and made popular by Italian immigrants in their restaurants and pizzerias, and then it came back to Italy and re-incorporated there and appreciated in a different way. Pizza is rather seen as an American type of fast food, rather than a purely Italian product. Similar things could be said about some Mexican dishes and their Texan equivalents.