Possible Clues:

• "That's cool"
• "Righteous, dude!" ... or, parsed differently, a hint to parts of the starred clues' answers
• 'That's cool, man'
• "Cool, dude!"
• 'Cool, dude!'
• 'That's cool, daddy-o!'
• 'Impressive!'
• 'Gotcha, man!'
• 'Cool,' to a cool cat
• 'Cool, man!'