The Ratio of Pagett [1983] Is Which of the Following

The ratio of Pagett [1983] is which of the following:

A) That the act of taking V hostage was a necessary condition for her death (or a causa sine qua non) and thus Pagett was guilty of manslaughter?
B) That the police officers had broken the chain of causation because they had acted unreasonably and thus Pagett was not guilty of manslaughter.
C) That in order to constitute a novus actus interveniens, a third party intervention had to be voluntary, ie: free, deliberate and informed, e.g.: not a reasonable act in self-preservation or an act done in performance of a legal duty.
D) That causation is always a question of law.