When a hypothesis is proven wrong, scientist often begin in revising the?

Members of the common school movement believed that

Which action by the us war department angered chief red cloud to the point that he refused to sign the treaty of fort laramie ? a) the killing of buffalo by the united states troops b) the appointment of troops to the powder river basin c) the burning of parts of the powder river basin d) the murder of chief red cloud’s wife

What is the name of the social stratification set up by the vedic peoples of the indus river valley civilization