What happens next in this paragraph?

Several people are riding horses in an outdoor arena. They are involved in a game of polo. they
Pick your answer from:
(I). are also represented by playing the horses, kicking them, and kicking off their riders..
(II). shoot at each other with long sticks..
(III). fix the stirrups before adding them back and forth..
(IV). hit the ball back and forth with sticks while riding the horses..
(IV).