What Is the Meaning of the Doctrine of

What is the meaning of the doctrine of

A) The term means that the Commission must bring proceedings before the ECJ against a Member State when it is clear that a Member State has breached EU law.
B) The doctrine means that Article 267 (3) TFEU imposes an obligation upon the courts of last instance to ask for a preliminary ruling each time the interpretation of EU law is at issue.
C) The doctrine means that Article 267 (3) TFEU imposes no obligation upon the courts of last instance to ask for a preliminary ruling when the correct application of EU law is so obvious as to leave no scope for any reasonable doubt as to the manner in which the question raised should be resolved.