Tom Wakes Up with a Tremendous Hangover and Slowly Walks

Multiple Choice

Tom wakes up with a tremendous hangover and slowly walks into the kitchen. His roommates start teasing him about his crazy dancing at the party the night before, and how he was "making the moves" on a certain girl. Tom painfully shakes his head, "No way-I didn't do that!"
To which his roommates reply: "Oh yes you did, buddy, and we have the pix to prove it! Ha-ha!"
Looking at the photo, Tom says, "Nope, I don't remember that-at all!"
What alcohol-related phenomenon is Tom experiencing?

A) Pregaming
B) Hangover
C) Blackout
D) Erectile dysfunction