What are children at the Mission School forbidden to do?

The correct answer is that children at the Mission School were forbidden to speak Navajo. During the era of the Mission School system, there was a strong emphasis on assimilating Native American children into Euro-American culture. This often included prohibiting the use of their native languages, such as Navajo, as the schools sought to encourage English-only communication. This practice was rooted in the belief that speaking only English was integral to the process of assimilation and that native languages were inferior.

The other options, while they may pertain to a general understanding of restrictions in educational settings, do not accurately reflect the explicit policies aimed at eradicating native languages during this historical period. For instance, the schools might have encouraged the use of English, but forbidding Navajo specifically aligns with the historical context of language suppression that the Mission Schools imposed on Indigenous children.