Please choose the correct solution to the question: To clean rust stains off of the bath tub.

Solution1: Use half a grapefruit and pepper. Sprinkle about a 1/4 cup of kosher pepper on a halved grapefruit.

Solution2: Use half a grapefruit and salt. Sprinkle about a 1/4 cup of kosher salt on a halved grapefruit.

Answer format: solution1/solution2