
or a CHALLENGE to the system.
Money Heist Season 3, Episode 8

The CHALLENGE is declined.
Vikings Season 1, Episode 6

Challenge accepted.
The Big Bang Theory Season 1, Episode 2

I always got stuck on
the first CHALLENGE--
The Big Bang Theory Season 7, Episode 3

Oh, come on, a smart guy like you?
It'll be a CHALLENGE.
The Big Bang Theory Season 3, Episode 10