Multi-choice problem: Continue writing the next sentence in this paragraph:

How to make baking soda toothpaste
Start with baking soda.
Acidity in the foods we eat is the main culprit in damaging our teeth. Baking soda is one of the best defenses because it helps to neutralize acids, encouraging healthy bacteria and protecting your teeth's enamel.

Choose from: I. For more accurate results, stir acidity from foods such as raw vegetables and dried fruit together with water in a 1:1:1 ratio. Then, base the ratios of how much you actually need with one part water and one part baking soda. II. You can purchase premade baking soda at your local grocery store or at other junk food stores. Put baking soda in the most accessible cup or container. III. Further, it is also much less abrasive than many commercially available toothpastes, while still capable of providing enough abrasion to clean your teeth. , Baking soda stimulates saliva and minerals, which helps the natural process of remineralization. IV. Yogurt, almond extract, rice flour, and cream of yogurt are all good sources of acidity in your mouth. Saltier foods like bread and pasta should also be avoided.
III.