a. open land in the Southeast to American farmers.
Explanation:
Congress passed the Indian Removal Act in 1830. The purpose of this Act is to "open land in the Southeast to American farmers."
This is evident in the fact that the United States Congress preferred to make more land accessible in the Southeast to white settlers, thereby ensuring that the law or Act made compelled the Native Americans living east of the Mississippi River to move to the western part of the River.
