True or false: time of day is also a factor that increases everyone's risk

How harmful is it to smoke a pack of cigarettes a week?

Where are teens exposed to ads about tobacco products? on the radio in magazines near schools on television

How is the central idea developed further? (a) the author elaborates on the treatments for allergies in adults and how they work. (b) the author quotes the reactions of experts and the methods used to conduct the study. (c) the author compares the different rates of food allergies shown in children and adults. (d) the author indicates the limitations of the study because of differences in health care.