This is a test of commonsense with single/multi-choices. Complete the next sentence:

A dance class is choreographing a routine and everyone is generally in sync with each other. they

OPTIONS: (a). all take turns marching and performing kicks and flips.; (b). march back and forth in place as they move straight and then stop.; (c). all add one into the group with their own team.; (d). move back and forth, up and down, and shake their chests.;
The answer is:
(d).