What are the three eras of the evolution of world expositions?
A.
The era of industrialisation, the era of cultural exchange, and the era of nation branding.
B.
The era of industrialisation, the era of cultural exchange, and the era of knowledge.
C.
The era of cultural exchange, and the era of nation branding, and the era of technology.
D.
The era of cultural exchange, and the era of information, and the era of technology.