Jack, a Landlord, Sells His Apartment House to Bob, Who

Jack, a landlord, sells his apartment house to Bob, who knows that each of the four apartments is rented. May Bob tell the tenants to vacate and install his own tenants?

A) Yes, since he is now the owner.
B) Yes, the leases terminate when Jack's ownership ends.
C) No, he must wait until their leases expire.
D) No, they may stay as long as they wish.