Quais são os direitos das crianças na era digital?

Witch sentence contain an adverb clause

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

If the author of the gift of the magi had made the reader aware of the gifts that jim had purchased in the beginning of the story this would be an example of