What happens next in this paragraph?

This young woman is in the studio playing the piano. no one else
Choose from: (I). is around to distract her and she starts to dance very intensely at first.. (II). appears to be paying any mind to the woman playing the piano and she is stuck until the music stops.. (III). is there to play for her, they just watch the whole thing.. (IV). is in there with her and she looks very serious about what she's doing..
(IV).