1.A bought a car from B, a dealer of cars, on the installment plan. After a while, A brought back the car to the shop B, saying he could not pay for it. B accepted the car and registered it under its (Bs) name. for a long time, B did not communicate with A and asked for the unpaid balance. Later, A received an account for the cost of spare parts and for gasoline. B then brought this action to recover both the unpaid balance and the new account. Has As obligation been extinguished?