Multi-choice problem: Continue writing the next sentence in this paragraph:

A blue slack line is attached to two trees outside in an open field. on the line

Pick your answer from: A). , people are riding in a tight line and sometimes crashing into other people on the line.; B). , a man is tied up to his bent over lawnmower.; C). , there is a man bouncing up and down while standing on the line before he gets off.; D). , dogs are lay out, ready to be removed by the owner on a blue slack line.;
C).