Answer:
Rubio can include an audio clip of an interview with a doctor who recommends swimming as excellent exercise.
Step-by-step explanation:
This is the best element that Rubio can include in his presentation. The purpose of the multimedia presentation is to encourage children to join the team, but also to convince parents of the advantages of this decision. It is likely that the parents' main concern is their children's well-being. Therefore, the best thing that Rubio could do would be to highlight the advantages of swimming for children, particularly in terms of health.