The answer to the question is control for the type of headache, stress, migraine, or other causes and randomly assign each person to either the treatment or control group.
The most prominent symptom of a migraine, a common neurological condition, is a throbbing, pulsating headache on one side of the brain. Physical exertion, bright lights, loud noises, or strong smells will probably make your migraine worse. It could endure for days or at least four hours. 12% of Americans are thought to have this hereditary disease. It is the sixth most incapacitating disease in the world, according to research.
To learn more about migraine with the help of given link:
https://brainly.ph/question/205065
#SPJ4
