What happens next in this paragraph?

How to clean blood from walls
Treat blood stains as soon as possible.
Blood stains will set over time and may seep into deeper layers of your wall, making them more difficult to remove. If possible, clean up a blood stain as soon as it occurs.
Choose your answer from:
[I] That way the stain will be less noticeable at night. Generally, the sooner you are treated the better your results may be..
[II] While it is not necessarily necessary, it may be a good idea to do a test run. Wash the stain with soap and water, and look for debris..
[III] If you are vacuuming your walls or if someone else has come into your home and you spot blood, you should immediately use stain remover to remove it from the walls or floor. If necessary, replace the rubber coating on the walls with a new wax (or other petroleum-based solution)..
[IV] Remove as much blood as possible before starting any cleaning. If the blood is still wet, use a cloth or paper towel to soak it up..
[IV]