Q: In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".
[header] How to prove murder [title] Identify first degree murder. [step] There are generally two kinds of murder: first degree and second degree. Each requires different mental states. <sep> (A) Research your state's rules of evidence. If you don't have any proof, then you might not be able to prove murder. (B) [substeps] First degree murder is a case where the person is convicted of a crime of which the evidence is not of a suitable degree. This means at least no personal damage is caused by the crime. (C) [substeps] Second degree murder is the most common type of murder. Even in first degree murder, the victim (s) are not personally liable. (D) In other words, what separates first degree from second degree murder is what the defendant was thinking. [substeps] First degree murder is an unlawful killing that is willful and premeditated.
A:
D