This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to age aluminum
Rough up the surface with sandpaper.
If you want a truly distressed and aged look, but are working with shiny, new aluminum, you can sand it down. Use 80-grit sandpaper to rough up the surface of the metal.

Choices: 1. Use a bit more sandpaper than you need for the piece as you sand. Work with the grain of the metal using short, even strokes to avoid creating ridges in the aluminum. 2. Spray your aluminum with bleach. Wear a mask and protective gloves when working with bleach. 3. Sandpaper makes the scratches and crevices less noticeable, and makes them easier to clean. Add a primer or a coating to the aluminum when sanding. 4. At this point, you will need to know if the aluminum is " shiny ". The best sandpaper isn't rough: it's coarse.
The answer is:
2.