Also , on Thursday , because I was not feeling well , I did n't run . I caught up on Sunday ( though not with running , but by moving furniture and boxes up and down two flights of stairs continuously for 3 hours . I was too exhausted to move afterwards , let alone run !
What may be the reason for using the stairs ?
Pick the best answer from the following options:
- They building has easy to use staircases .
 - None of the above choices .
 - They did nt know how to use the elevator .
 - They used it as exercise to work up a sweat .


None of the above choices .