Final answer:
Rescission by an unpaid seller allows for the termination of a contract when possession of a residence cannot be delivered on the agreed date, relieving both parties from their obligations, with the option to adjust the contract if termination is not chosen.
Step-by-step explanation:
The effects of rescission by an unpaid seller are significant in the context of legal agreements and real estate transactions. In the scenario given, if an owner is unable to deliver possession of the residence to residents on the contracted date, the contract can be terminated by either party through written notice. This mutual termination releases both parties from their obligations under the agreement. If neither party opts for rescission, the contract can be adjusted to start from the actual date of possession, with the terms being prorated accordingly.