<span>The question is asking us to choose, from a list, which activity can substantially increase the activity level of a person lifestyle. The activity here is the physical activity, so the question is, which of the following would make you most physically active. The answer is walking to school - here you would be using your muscles to move. When you are driving a car or using an escalator, you are using technology to move so you don't have to use physical strength.</span><span />
1.B without regular cardio workouts, you will have a very hard time breathing
2.B all of those CAN give accurate info, but gov. studies are best due to the amount of people they question
3.C the AHA does reliable experiments that proves helpful
4.D gov wellness sites usually give old or washed down advice
5.B if your muscles aren't used to physical activity, they will respond a bit more "aggressively" for lack of a better word