A blonde, a brunette, and a Redhead are all in a bar

The bartender goes up to them and says "Hey ladies, I can grant you a wish if you can tell me one true statement."
"However if you lie to me, you will disappear.
Skeptical, the redhead goes up first and says
"Okay, then I think I am the prettiest one in this room."
The bartender says
"True, what's your wish?"
The redhead wishes for a diamond necklace and receives it and leaves the bar happy. Surprised, the brunette goes next eagerly and says
"Okay, I think I am the smartest one in this bar."
She then wishes for a brand new car and receives it and runs out of the bar happily.
The blonde eagerly says to the bartender
"Okay, I think..."
And she disappears into thin air.