The constitutional reforms already happened in 1982. The issue is how courts apply the constitutional language contained in those reforms.

The problem isn’t that aboriginal peoples haven’t been able to “gain full ownership of land.” The problem is inconsistent recognition and establishment of aboriginal rights.

This best captures the main point, which is expressed at the end of P1.

(D) doesn’t capture that idea that the burden of interpreting general constitutional language has resulted in inconsistent recognition and establishment of aboriginal rights. (D) is too narrowly focused on some courts’ decisions. But the author brought up a court decision in the last paragraph to support the broader main point expressed at the end of P1.

(E) doesn’t capture that idea that the burden of interpreting general constitutional language has resulted in inconsistent recognition and establishment of aboriginal rights. Although the author mentions the Supreme Court at the end, that reference is in connection with an individual provincial court decision, and that decision is brought up to support the broader main point expressed at the end of P1.