Concept: Ahab’s reign was marked by official adoption of Baal worship, which became Israel’s great national sin.Explanation:Under King Ahab and Queen Jezebel, Israel turned to the worship of Baal and Asherah, rejecting the LORD.The biblical record repeatedly names this idolatry as the chief sin of Israel during Ahab’s reign.Therefore, the sins of Israel consisted mainly of worshipping idols, not merely social injustice or temple desecration.Answer: A. worship of idols