Write the next sentence in this paragraph:

A strong man is lifting his legs up and down across parallel bars. he

Select from the following.
[I] is sitting at a bench watching how his feet move back and forth on the padded bars as he sits..
[II] stands up on a mat..
[III] is holding onto two rings on the middle of the bars..
[IV] begins to do shrugs on the bars..
[IV]