Will upvote!

what is the most likely explanation for why the shang had little interaction with non-chinese cultures?

a) they were unable to travel upon the yellow river.

b) they were surrounded by higher plains and mountains to the north and west.

c)they were not aware of the other cultures existing nearby.

d) they were unable to use the seas to establish trade with others due to lack of technology.

i'm in between b and d but idk. : /