Joel's Car Broke Down on a Dark, Rainy Night

Joel's car broke down on a dark, rainy night.Along came Andy in his four-wheel drive truck with tools and supplies in the back.Joel didn't have any credit cards and had only $3.25 cash, so Andy told him to write a check or an IOU.Neither Andy nor Joel had any paper, so Joel wrote on the cover of Andy's lunchbox: "If my car is fixed right by Andy Walcott, I will pay him $150.(Signed) Joel Boyd." Andy indorses the note and takes it to a commercial factor for negotiation.The factor refuses, saying it is non-negotiable because:

A) it is written on a lunchbox.
B) it mentions the existence of a contract to repair the car.
C) it is conditional on satisfactory repair of the car.
D) All of these.