This is an example of dramatic irony. Dramatic irony is when the audience is aware of what's happening but the characters aren't.
The answer would be option B "Johnny." Johnny died in the hospital because of the fire. It was from the burning down church and Pony, and Johnny went in their to save many little kids. It's not option A because Two-bit doesn't die at all, it's not option C because Ponyboy doesn't die either, it's also not option D because Dallas died in a gun fight with the police.
Hope this helps!
