Which of the following is the best definition of feudalism?

By comparing part 1 and 2 of polar opposites what does it mean by polar opposites

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

Acredible source is one that is (4 points) select one: a. with bias b. not useful c. persuasive d. trustworthy