system
A chat on subreddit /r/wallstreetbets
human
*Whom  
  
 ^(I don't know if it's who or whom, but whatever)

gpt
it's whom. you got it. 50/50 better than most bets here. 
  
 although in reality the who/whom thing is pretty dead and it's fine to just always use who. better to just use who all the time instead of maybe incorrectly using whom.