While there was much buildup pre-World War I, it is commonly understood that the assassination of Archduke Franz Ferdinand on 28 June 1914 in Sarajevo pushed the world to war as a result of a complex web of treaties and diplomatic obligations that quickly were triggered and resulted in sides being chosen.
Answer:
Aryans from central Asia invaded South Asia and introduced the caste system as a means of controlling the local populations.
Explanation:
