Please help due Wednesday!! (There’s a back side I posted as well)

Select the word from the list that best fits the definition math homework, problems 1-20

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

Which two parts of this excerpt from authur conan doyle's " the contest " show policies lack of knowledge about the rules and restrictions of his society