This map shows both the Tang (618–907 AD) and Yuan (1271–1368 AD) ancient Chinese dynasties.

Which statement best describes what is shown on the map?

a
The Tang Dynasty focused on expanding into desert areas.
b
The Yuan Dynasty more than doubled the size of the Tang Dynasty.
c
The Yuan Dynasty expanded eastward during its reign.
d
The Tang Dynasty’s territory matched the land area of the Yuan Dynasty.