
That's it. The Sheldon Cooper
Girlfriend Challenge is officially live.
The Big Bang Theory Season 9, Episode 8

The CHALLENGE is declined.
Vikings Season 1, Episode 6

There would be greater shame
in accepting a CHALLENGE from a criminal.
Vikings Season 1, Episode 6

I see no other option than
to CHALLENGE you to a duel.
The Big Bang Theory Season 5, Episode 17

You really want to CHALLENGE yourself,
you could learn to speak Hindi.
The Big Bang Theory Season 10, Episode 22