I believe the answer is: A. The church combined both Greek and Roman architecture, and became a melting pot where Eastern and Western cultures came together.
The combination became a proof of Cultural Assimilation that occurs between eastern and western church due to the good relation that exist between them. This indicate that in the past people from Byzantine and Roman empire were free to visit each other's region either for business, tourism , or studying.
Because of the French immigration?
The correct answer is The Wealth of Nations.
This novel was written by Adam Smith, a famous economist and philosopher. In it, he described what a nation's wealth is, and how to achieve it, which makes it instrumental for the Free Enterprise system as we know it today. Before this book, it was much different.