What Has Been the U

What has been the U.S. Supreme Court's rationale in prohibiting the imposition of mandatory life sentences without possibility of parole for juvenile offenders?

A) The sentence is cruel and unusual in that it separates the child from his family forever.
B) The sentence does not take into account biological harm already done to the juvenile.
C) The sentence is cruel and unusual in that no other country treats youthful offenders in such a harsh manner.
D) The sentence doesn't take into account that criminal tendencies may be outgrown.