Finish the following sentence with the best choice: What should I do with my windows during the summer?

Choices:
- Once the sun goes down and the air cools, it’s time to open them up and let some fresh air in.
- Once the sun goes up and the air warms up, it’s time to open them up and let some fresh air in.

Answer:
Once the sun goes down and the air cools, it’s time to open them up and let some fresh air in.