What Caused the Series of Calamities That Gripped the near East

What caused the series of calamities that gripped the Near East from about 1200 to 1000 B.C.E.?

A) Droughts that spread across the area, stopping the alluvial floods of river systems and causing widespread famine
B) Civil war in Greece as well as foreign invasions by different bands of marauding armies, called Sea Peoples, who attacked Egypt, the Hittite kingdom, and as far inland as the Babylonian kingdom
C) Social unrest in Egypt, central Anatolia, Palestine, and southern Greece, caused by the spread of monotheism
D) A power vacuum left by the decline of Egypt and the ensuing competition for domination of Egypt's coveted trade routes