Which Is True About the Mechanism for a Diels-Alder Reaction

Which is true about the mechanism for a Diels-Alder reaction?

A) The mechanism requires the reaction of two dienes.
B) The product will have more π bonds than the starting materials.
C) The mechanism typically requires an electron-poor diene.
D) The mechanism proceeds through an aromatic transition state.
E) The mechanism requires only two steps.