Answer:
Adam (A)
Step-by-step explanation:
After Eva throws it to Adam, Adam has to throw it to either Issac or Urban. That would be the second throw. The third throw is either from Issac to Urban or the other way around, because they have to throw it to another boy, but not Adam, because he's the one whi passed it to them. The fourth throw will be from either Issac to Adam, or Urban to Adam, again, depending on who Adam passed it to. (If Adam had passed it to Issac, the third throw would be Issac to Urban, and Urban would have to throw it to another boy on the fourth. This would be Adam, because he can't pass it back to the boy who threw it to him. The same reasoning applied if Adam had passed it to Urban.) This way, Adam will be making the fifth pass. Hope I could help you!
