Final answer:
Susan must vacate immediately because the life estate ended with Mary's death, which also ended Susan's lease, granting full ownership and control of the property to Mary's daughter, who is now the rightful owner.
Step-by-step explanation:
The correct answer to this scenario is A) Susan must vacate immediately. Since Mary had a life estate, her interest in the property terminated upon her death, and the remainder interest vested immediately in her daughter. The lease that Mary granted to Susan was dependent on Mary's life estate; thus, it too terminates upon Mary's death. Since the remainderman, Mary's daughter has both a present interest in the property and is the rightful owner after Mary's passing, she has the authority to serve notice and require Susan to vacate the property. Unless specific legal provisions or terms of the lease explicitly state otherwise, the general rule is that leases contingent upon a life estate terminate with the life estate.