Answer
Yugoslavia was the country represented by Ćosić in basketball. Ćosić was a renowned Yugoslav basketball player who played for the Yugoslav national team and several European clubs. He was a key member of the Yugoslav team that won the gold medal at the 1980 Summer Olympics and the silver medal at the 1968 Summer Olympics. Ćosić was also a two-time EuroBasket champion and a three-time Yugoslav League champion.