Finish the following sentence with the best choice: To clean rust stains off of the bath tub.

Choices:
- Use half a grapefruit and pepper. Sprinkle about a 1/4 cup of kosher pepper on a halved grapefruit.
- Use half a grapefruit and salt. Sprinkle about a 1/4 cup of kosher salt on a halved grapefruit.

Answer:
Use half a grapefruit and salt. Sprinkle about a 1/4 cup of kosher salt on a halved grapefruit.