Antonym of CHALLENGE

Answer: Option B

Challenge : a call to someone to participate in a competitive situation or fight to decide who is superior in terms of ability or strength.
Admire : regard with respect or warm approval.
Accept : consent to receive or undertake (something offered).
Favour : approval, support, or liking for someone or something.
Praise : express warm approval or admiration of.

Antonym of Challenge is Accept