Which ONE of the Following Is a 'Court Authority

Which ONE of the following is a 'court authority'?

A) It is a case that is mentioned in the moot problem.
B) It is a case that is given to the mooters by the judge, which they are required to incorporate into their submissions.
C) It is a term used to describe any case that was decided in the same court as that in which the moot is heard: i.e. if the moot is heard in the Court of Appeal, all Court of Appeal cases would be called court authorities.
D) It is a term used to describe a case that was decided in a higher court than that in which the moot is heard and which is therefore binding on the moot court.