What physical feature had the greatest effect on China's contact with other countries? O Vast, flat deserts made northward travel easier.
O Extensive highlands made westward travel difficult.
O River systems helped travel between north and south.
O High, dangerous mountains blocked southward travel.

A. vast, flat deserts made northward travel easier.

Explanation:

i got it from another question just like this one so if its wrong i'm sorry. they just keep saying in the comments that it was A . so if i'm wrong i'm sorry

it was certainly a debatable decision, mainly because it was based primarily on political - and not on legal or social - views. since the congress at that time was led by members of the republican party, and the territory that the tribes wanted to turn into an exclusively indian state was predominantly democratic, the proposal (as expressed in the constitution) did not succeed, but the constitution itself proved to be of crucial importance in the creation of the state of oklahoma, and, most importantly, it guaranteed the involvement of representatives of the indian tribes in the government of the future joint state.  

as a member of congress, i would have voted to ratify the constitution, or at least to have it tabled. ignoring it was an interested and partial decision.