Plus , I got to hear the worst riddle I ' ve ever heard from a bum . " What 's the best nation there is ? " " Uh , Kenya ? " " No , a donation . "
What may be the reason for a bum giving them a riddle ?
Pick the best answer from the following options:
- None of the above choices .
 - To let them through .
 - To test their knowledge .
 - To earn money from them .


To earn money from them .