1 a: something (as a sum of money) risked on an uncertain event : stake b: something on which bets are laid : gamble <do a stunt as a wager>

Which one the given definitions of 'stunt' fits best in the bold part?

1: an unusual or difficult feat requiring great skill or daring ; especially : one performed or undertaken chiefly to gain attention or publicity2: a shifting or switching of the positions by defensive players at the line of scrimmage in football to disrupt the opponent's blocking efforts

[All definitions are from M-W's Col. Dic.]
Many stunts are performed by stupid people (or kids) as a the result of a bet.

"I'll bet that you can't climb to the top of that tree"
"I bet you can't eat 5 giant sized hamburgers in 10 minutes"

Just take a look at the people who try to get in the Guiness book of records, for example:

Jackie Bibby sat in a bathtub with 87 poisonous rattlesnakes snakes for 45 minutes.
AlpheccaStarsJust take a look at the people who try to get in the Guiness book of records
Recently I was watching Guinness World Records show and I was just going to puke. They were eating worms and doing things which you can't even imagine in your wildest dreams.

Jackie Bibby, the Texas snake man, is one step ahead of stupid people. Well, I must say he is a 'crazy' brave man.