Should i start nate washington, derrick mason or marion barber in my flex position?

I am playing yahoo fantasy football. need someone to fill this spot. need helpShould i start nate washington, derrick mason or marion barber in my flex position?
Agreed. Marion Barber no doubt about it.Should i start nate washington, derrick mason or marion barber in my flex position?
Barber. no doubt
barber no question