Reasons why Kenny is the only person who makes sense.
First of all let's use our heads. Okay, first Lilly. I'm not saying it isn't Lilly, I'm just saying it's highly unlikely. Clementine knows Lilly was in the military and can handle herself, even when stranded on the side of the road or because of a radiator being useless after 30 miles. Plus, Clementine has no reason to believe she is dead.
Next up, Molly. Molly makes less sense than Lee or Glenn. She specifically said in front of Clementine she is fine on her own and doesn't need a group. Also, Clementine has no reason to believe she is dead.
Lee makes as much sense as Larry surviving a salt lick to the face.
Glenn is either with Rick (TV Show) or I believe dead (Comics).
Next, Michelle. If Christa had time to mourn Omid, she probably made sure Michelle was dead.
Sorry but BrOmid is gone .
I believe the cancer patients specified Vernon is gone. Whether he's dead or not. I don't think Clementine believes he is dead.
The man you give water to (Victor), is a good answer too. However, I don't think he is alive. If he is, he probably is resting.
Lee is 100% dead. There's no probable chance a dead-eye shot like Clementine would miss the shot. Even if you leave him, he becomes a walker. Lee cut his arm off a little too late.
While Christa does make sense, Clementine doesn't think she is dead. And Christa told Clementine she doesn't trust other groups. Why would she lie to Clementine? I believe Telltale will bring her back, just not right now.
Finally, the moustached badass, Kenny. He makes the most logical sense. Clementine thought he was dead. Even if she didn't know, I believe BrOmid or Christa would've told her. Plus, we never saw him die. The game even specifies he was "lost" to the herd, while everyone else who died had the word "dead". Finally, Telltale said his fate would be explored. I don't think "fate" means his death. It's impossible for just one walker to walk from Savannah to North Carolina.