Why was there such a push in the late 18th century to "civilize" native americans?

a more native americans could go to school in london if they were "civilized."

b more american parents could adopt native american children if tribes were "civilized."

c it was thought that native americans could be trained for the army if they were "civilized."

d it was thought that making native americans "civilized" was a "moral" solution to the indian problem.