Public Buildings in the United States Are Required to Be

Public buildings in the United States are required to be accessible to the disabled and,as a result,almost all have an elevator.What would be an example of a positive direct incentive for those who can to use stairs?

A) Using the stairs will make it seem that they care about their health and that they aren't lazy.
B) Using the stairs will increase the risk of tripping and falling.
C) Using the stairs will take more time than taking the elevator and will increase the risk of missing an important meeting.
D) Using the stairs will give them some exercise and make them healthier.
E) Using the stairs will put elevator repair professionals out of work.