American Government! Please help!

Why did the Supreme Court rule that burning the American flag is a form of free expression but that burning a cross, in some cases, is not a form of free expression?

A. They argued that burning a cross is the same as burning a draft card and therefore not protected.
B. They argued that burning a cross is more offensive than burning a flag and therefore not protected.
C. They argued that burning a cross in political protest is symbolic and therefore not protected.
D. They argued that burning a cross to scare people was threatening and therefore not protected.