Final answer:
The owner can save money by renting points online rather than borrowing points by phone. The correct option is 45 days in advance of check-in.
Step-by-step explanation:
The answer to the question can be found by comparing the two options: borrowing points by phone at $10 per 1,000 and renting points online at $8 per 1,000. We need to determine the number of days in advance that the owner can borrow or rent points.
Let's consider the phone option first. If the owner borrows points by phone, they will pay $10 per 1,000 points. So, if they want to borrow 1,000 points, it will cost them $10.
If they want to borrow 2,000 points, it will cost them $20. This means that for every 1,000 points, the owner pays $10.
Similarly, if the owner rents points online, they will pay $8 per 1,000 points.
So, if they want to rent 1,000 points, it will cost them $8. If they want to rent 2,000 points, it will cost them $16. This means that for every 1,000 points, the owner pays $8.
Since borrowing points costs more ($10) than renting points ($8) per 1,000 points, the owner should choose to rent points online to save money. Therefore, the correct option is b) 45 days in advance of check-in.