so I go for the first one.
"What are the odds?"
Odds by itself refers to the chances that sth might happen but it is highly dependent on the tone of the speaker.
1- When it is used as a real question it is obviously asking how likely sth might happen.
Example:
--Micky: A meteor might hit the earth.
--Joe: What are the odds?
--Micky: I'm afraid it's a 80% possibility
2- But when it is used as a rhetoric question or as an exclamation (this is more commonly used) it expresses surprise for an unlikely outcome". In other words, it is trying to state a strange or somehow interesting situation
Example:
--Hi, I am Nicolas.
--Oh, hey, my name is Nicole.
--Wow, what are the odds, huh?
Here as u might have guessed it means " Wow that is interesting' or 'wow what a remarkable coincidence'.
3- Another instance of this expression that I've heard of in LOST TV series was used in a sarcastic tone! Based on its context it seemed that it means "what's the point?" or somehow "So what?"
I hope u find this expression useful!
P.S. These examples and information are gathered from English forums.