When National Law and EU Law Are at Odds with Each

When national law and EU law are at odds with each other, which of the following statements is TRUE?

A) National courts are prevented from raising questions about the nature of EU law and cannot consult the CJEU.
B) National law should be applied first, and EU law only if the CJEU demands it.
C) National law always supersedes EU law.
D) EU law supersedes national law in areas where EU law applies.