The prophet Obadiah delivers a short but powerful message against Edom. What is the primary reason for God's judgment against Edom, according to Obadiah's prophecy?

A Edom's failure to assist Judah during its time of distress and its gloating over Judah's downfall. B Edom's idolatry and worship of false gods. C Edom's economic exploitation and mistreatment of neighboring nations. D Edom's military aggression and expansionist policies that threatened regional stability.