Which features formed natural barriers to expansion and invasion for China? Select all that apply

Question

A. Bay of Bengal
B. Gobi Desert
C. Himalayas
D. Tien Shan mountains ***
E. Yellow River

Answer 1

And what else??

http://np.china-embassy.org/eng/ChinaABC/dl/W020041027375429228697.jpg

Answer 2

And what else?

Answer 3

I NEED THE WHOLE DAMN TEST!