Final answer:
American Indian boarding schools controlled students by forcing them to speak only English, banning traditional cultural practices, and separating siblings and forbidding communication. option 4.
Step-by-step explanation:
The best example of how American Indian boarding schools controlled students is option 4) All of the above. These schools were established with the purpose of assimilating Native American children into white society, and they employed various methods of control. Forcing students to speak only English, banning traditional cultural practices, and separating siblings and forbidding communication were all tactics used by these boarding schools to strip Native American children of their culture and identity.