Please choose the correct ending to complete the given sentence: Home and Garden: [header] How to clean the bottom of an iron [title] Mix a 1:1 solution of vinegar and salt in a saucepan. [step] Place the pan on the stove and heat the mixture until the salt dissolves. You can stir occasionally to help this process along.

Ending1: [substeps] Vinegar is actually alcohol-based and has properties that help distinguish it from white vinegar, but it is also surface safe, although it can take longer to prepare and it must be sterilized. [title] Place the solution in the pan and cook it until it dissolves. Ending2: If the pan requires heat you can add activated charcoal or 30 drops of liquid dishwashing liquid. [substeps] You should see a film on the bottom pan when you are done. Ending3: Make sure you remove the saucepan before the vinegar starts to boil. [title] Dip a clean rag in the heated vinegar-salt solution. Ending4: The hot vinegar will help break down the stains and dirt. [title] Rinse and wipe away the solution.

Answer format: ending1/ending2/ending3/ending4