Related Clues:

• 'Who'd a thunk it?!'
• Doubting words
• 'No kidding?'
• Doubter's words
• Start of a speculative comment
• "Yeah, sure, sure"
• "Oh, suuure"
• "Oh, really?"
• "Not likely!"
• Doubter's reply
• Skeptic's challenge
• Skeptical reply
• Response of disbelief
• Disbeliever's comment
• 'Mmm hmm ...'