What is the meaning of the word "challenge"?

Definitions:

a demanding or stimulating situation noun
- they reacted irrationally to the challenge of Russian power
questioning a statement and demanding an explanation noun
- Their challenge of my argument was unfounded.
to ask for identification verb
- The illegal immigrant was challenged by the border guard
to issue a challenge to verb
- I challenge you to a duel!
to raise a formal objection in a court of law verb
- I challenged the judge's ruling.
to take exception to verb
- I challenged their claims.