Write the next sentence in the following story.

How to keep teeth white while smoking
Brush your teeth.
Although this is important for everyone's dental health, tooth brushing is especially important for keeping a smoker's teeth white. Brush your teeth twice to three times a day, being sure to brush for at least two minutes each time.

Possible answers:
(1). Remember to always brush before and after you smoke, as this can help prevent your teeth from getting inflamed. You can also use toothpaste when you blow.;
(2). Clean your mouth with mouthwash and a fluticasone minty breath rinse, especially before and after smoking. The enamel on your teeth is compromised.;
(3). Use a whitening toothpaste if you would like to get an extra level of whitening action. Smokers tend to have poorer oral health and a higher risk of periodontal disease, so it's important to focus on keeping your mouth healthy.;
(4). All of the other areas of your mouth should be brushed as well. Be sure to brush at the corners and the crevices of your teeth and gums so that you can be even.;. The answer should be
(3).