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

How to render a wall
Chip away any old render and paint.
Use a cold chisel that is just sharp enough to scrape, chip away any bumps, dripping render, paint, or mortar that's stuck to the wall. Sometimes the old render may flake off and you'll want to scrape it all away before applying the new render.

Options are: +When scraping, keep the paint in mind. It can chip over time, making it harder to get it out of the wall. +Make sure that you are wearing gloves and safety equipment so that the render is not visible after chipping out the render. Sand the wall down with 220 grit sandpaper. +If the old render is exceptionally brittle, you may be able to chip it free with a standard filler sheet. Otherwise, it won't come off as easily. +Continue to chip away at the wall until the stone or brickwork is free of bumps. Scrub down the wall with a stiff bristled broom.
The answer is:
Continue to chip away at the wall until the stone or brickwork is free of bumps. Scrub down the wall with a stiff bristled broom.