51. S, the owner of a rent-a-car business , leased one of his cars to B for one month. On the day of the expiration of the lease and while B was still in possession of the car , B offered to buy the car from S for P200.000.00. Believing the price to be a good one, S readily accepted B's offer and then and there executed a deed of absolute sale in favor of B who immediately paid the price in cash . Thereafter B drove away from place of S. a. The delivery of the car by S to B is by constitutum possessorium