The idea being sold here is:
A. American Indian men are content to be told what to do by others.
Step-by-step explanation:
Adverting cannot merely just sell a product.
Some advertisements sell products through lifestyle
And grimmer still, some advertisements exist to make the ideas in the mind of the people so that the people behind the ad can do as they like.
This is one of those ads that makes a public opinion on a certain topic that they understand little about so they are gullible and get unconsciously subscribed to the idea of the text.
The idea here is the Indian is dependent on the white man but it is shown visually.