Final answer:
The HO₃ policy will pay for the cost of renting an apartment, but not the cost of the motel room.
Step-by-step explanation:
The HO₃ policy, which is a type of homeowner's insurance policy, will pay for additional living expenses if the insured's home is damaged by fire and they need to move into a temporary apartment. According to the information provided, the insured's sister stays in a motel while the repairs are being made because the largest available apartment in the area only has 2 bedrooms. In this case, the HO₃ policy will pay for the cost of renting the apartment, but it will not pay for the cost of the motel room. Therefore, the correct answer is 1) The cost of renting an apartment, but not the cost of the motel room.