(tell me why) which list includes only lifestyle factors that people can change to improve their health? a. having many friends, parents with heart diseases, sleeping 8 to 10 hours a night b. a family history of diabetes, lack of energy, thinking critically about health risks c. knowledge of common risk factors, level of physical activity, ways of reacting to conflict d. ways of interacting with others, changing the images in the media, resisting pressure from peers