Finish the following sentence with the best choice: To maintain your garbage disposal

Choices:
- once a month grind about about a dozen ice cubes. The ice will sharpen your blades and eliminate any grease trapped in the drain.
- once a month grind about about a dozen small rocks. The rocks will sharpen your blades and eliminate any grease trapped in the drain.

Answer:
once a month grind about about a dozen ice cubes. The ice will sharpen your blades and eliminate any grease trapped in the drain.