D-2

D-2 can refer to the following:
 * World D-2 from Super Mario Bros.: The Lost Levels.
 * Hit Rock Bottom, mission D-2 from Luigi's Mansion: Dark Moon.
 * Level 2-1 from Mario vs. Donkey Kong: Tipping Stars, labelled "Level D-2" in the Mario vs. Donkey Kong tech demo.

D-2