A leader at the front of a group is holding her hands in the air just like what all of the people facing her are doing .
It is probably the case that a Jazzercise instructor is waving her arms and showing her group what to do .
It is impossible that a Jazzercise instructor is waving her arms and showing her group what to do .
It is probably the case that a Jazzercise instructor is waving her arms and showing her group what to do .
A Jazzercise instructor is waving her arms and showing her group what to do .