Finish the following sentence with the best choice: How do you make sure a shelf is straight before hanging it?

Choices:
- Make a mark where you would like to place the fasteners for the shelf. Hold your shelf up in that area and place a level on it.
- Make a mark where you would like to place the fasteners for the shelf. Hold your shelf upside down in that area and place a level on it.

Answer:
Make a mark where you would like to place the fasteners for the shelf. Hold your shelf up in that area and place a level on it.