Multi-select problem: How does the next paragraph end?

They pick up speed and a young woman is skiing on the water at a very brisk pace. She goes back and forth and side to side in slow motion. the friends

Available options:
a). continue skiing through the room going over several snowy slopes.;
b). then hold the still image as they zoom in on her face as she goes quickly down the slopes.;
c). look back to see how she is doing.;
d). are holding a close close inspection of the bottom of the board as she goes down the slide.;
c).