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

Two young children come down the slope in red and black tubes. They come down steadily and smoothly till they reach the bottom of the slope. there

Options are:
a). are some other people climbing up the slope with tubes and sledges in their hands.
b). are some people standing near a water drop holding tubes.
c). they sit on the rails and wait for the lift to come before they get off the roller coaster.
d). is an interview with a reporter from the tv station and a news station talking about mountainous terrain and the people who are climbing to the bottom of the hill.
a).