How/ Why was serbia strategically important in WW1 ?

on Serbia's role and experience in the Great War encompasses several questions that still provoke controversies and offer many carefully reexamined data on issues such as war efforts in general, war casualties, war financing, refugees and prisoners of war. This account refers in brief to war aims, the occupation regime in Serbia (1916-1918) and lesser-known uprisings.

answer; ///i believe that the correct answer is (baldassare castiglione.

i would go with the last one