In 1989,the Supreme Court Overturned a Statute That Made Burning

In 1989,the Supreme Court overturned a statute that made burning the United States flag illegal because

A) they found it to be a "speech act" protected by the First Amendment.
B) they believed pornography was a more important issue to consider.
C) they were persuaded by the Berkeley Free Speech movement.
D) there were not enough cases to warrant a Constitutional amendment.