What is the best description of trade among northwest indians prior to the arrival of whites? huyyy plz

There was no trade among Indians prior to the arrival of the whites.  

Indians traded only among groups that spoke the same language.  

Indians traded among different groups, but only within a small area.  

Indians traded among numerous groups for goods that came from hundreds of miles away.  

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering