Write the next sentence in the following story.

How to cope with a spinal headache
Consume caffeine to constrict the blood vessels in your head.
Caffeine is a central nervous system stimulant and causes constriction of the blood vessels within your head.
Since headache is often caused by the dilatation of blood vessels, caffeine helps constrict them and counteract this effect.

Choices:
-- While caffeine can help dilate blood vessels, it's still important to consume it when you are experiencing dizziness or blurred vision. Do not consume more caffeine than recommended on the label.;
-- It can also help you see colors more clearly and stay sober by stimulating the blood vessels in your brain which are located within the cerebellum. Get additional relief by drinking vitamin c.;
-- Avoid alcohol, especially caffeinated beverages. Caffeine and alcoholics are both dependent on constant noise in the ear, which is why people with headaches commonly drink alcoholic beverages.;
-- Caffeine can be taken both orally and intravenously. A recommended dose of caffeine is 500 mg once or twice daily.;. The answer should be
Caffeine can be taken both orally and intravenously. A recommended dose of caffeine is 500 mg once or twice daily.