Despite Efforts to the Contrary, Why Is It Thought That

Despite efforts to the contrary, why is it thought that hate crimes are still underreported?

A) The enforcement officers may not recognize all hate crimes for what they are, and therefore some go unreported.
B) Many victims of such discriminatory crimes are afraid that reporting them will result in more harassment.
C) Some of the crimes are indirect, making them difficult to prove (e.g., property crimes as hate crimes) .
D) All of the above.