In the Context of a Case Report, the Ratio Decidendi

In the context of a case report, the ratio decidendi is:

A) The factual circumstances relied on by the judge or jury in making their decision.
B) The question of law required to be determined by the trial judge.
C) The judge's determination of the question of law by reference to the material facts.
D) A judge's remarks concerning matters other than the legal principle upon which the final decision is based.