Write a letter to your friend and give three reasons why he or she should be serious with education

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

Can someone me answer this english question

In a data source, such as a spreadsheet, why is it important that top row be the header?