X and Y entered into a universal partnership of all present property. At the time of their agreement. X had a four-door apartment which he inherited from his father 3 years earlier. Y,on the other hand, had a fishpond which he acquired by dacion en pago from Z. During the first year of the partnership, rentals collected on the four-door apartment amounted to P480,000; while fish harvested from the fishpond were sold for P300,000. During the same period. B received by way of donation a vacant lot from an uncle. The partners had an stipulation that future property shall belong to the partnership. Which of the following does not belong to the common fund of the partnership?

a. Fish pond

b. Vacant lot

c .Rental of P480,000

d. Apartment