Why do you think it is important for your answer to make sense? ?

How can behavioral science be applied in improving public health? a.by tracking a disease to determine its sourceb.by creating promotions that improve health habitscboth by tracking a disease to determine its source and by creating promotions that improve health habitsd.neither by tracking a disease to determine its source or by creating promotions that improve health habits

Pls, i really need on this question?

Why did the author include the fact that 40,000 african americans participated in the bus boycott