Which of the following correctly analyzes the effect the Supreme Court's use of selective incorporation has had on the freedom of expression? Choose the best answer.
A: Selective incorporation has expanded the freedom of expression by forcing states to protect the freedom of speech
B: Selective incorporation had no effect on the freedom of expression as states have always had to protect the freedom of speech
C: Selective incorporation had gradually reduced freedom of expression by allowing states to ignore certain freedoms found in the bill of rights.
D: Selective incorporation has limited the freedom of expression by only requiring the national government to abide by the freedom of speech