Que can mean that or who. It is that when a conjunction but it is who when you need it to be a pronoun.
Answer: the track team
Explanation:
Jake and Summer are teen detectives who solve cases given to them by their detective agency including the prevention of an art theft while they were in Mexico City by trying to solve a clue given to them on who could be behind the attempt.
In the episode, we learn that Jake is a member of the track team at his school and a very good one at that.
