Which research study would provide the MOST information about asthma and heredity?

Responses
A Asthma, Is It in Your Genes?Asthma, Is It in Your Genes?
B Asthma, Will I Grow out of It?Asthma, Will I Grow out of It?
C It's in the Air: Suffering with Asthma in the Inner CityIt's in the Air: Suffering with Asthma in the Inner City
D New Over the Counter Medications Prove Effective for Treating Asthma Symptoms