The correct option is B the law of the court in which case is tried
Lex fori is Latin for the laws of a forum and is a legal term used in the conflict of laws to refer to the laws of the jurisdiction in which a legal action is brought. When a court decides that it should, by reason of the principles of conflict of law, resolve a given legal dispute by reference to the laws of another jurisdiction, the lex causae, the lex fori still govern procedural matters.