Select from options: Continue writing the next sentence.

How to prevent tonsil stones
Brush your teeth regularly.
Failure to maintain good oral hygiene is a primary cause of tonsil stones. Brushing your teeth in the morning, before bedtime, and after every meal is the foundation of healthy oral hygiene and first step in preventing tonsil stones.

OPT: i. Use toothpaste made specifically for your mouth and cheek teeth to brush with. For best results, brush your teeth after meals, before you're drinking alcoholic beverages such as coffee and tea, and before you go to bed. ii. Hard-to-maintain teeth also make your system feel like the canvas for the growth of bacteria. Chewing gum regularly prevents bacteria, washing away the negative chemicals and saliva your mouth produces. iii. A regular brushing is preferred for those who do not have tonsil stones, but it may be a good idea to brush every day and after every meal. It is also a good idea to brush your tongue after every meal. iv. This will help eliminate food particles and bacteria that can collect in your tonsils' nooks and crannies. Remember to brush your tongue as well, since it can harbor easy to miss bacteria, mucus, and food residue.
Answer:
iv.