Who performed the first sucessful heart transplant

Frankie is having difficulty developing a friendship with histeammate curtis. whenever frankie invites curtis to hangout with him at the park, curtis always says that he's busy. what is most likely preventing a healthy relationship fromforming? a)the boys are not being generous with their time andeffort. b)the boys are not communicating. c)both boys are too busy. d)the boys are on different teams.