Concept:Jāhiliyyah refers to the pre-Islamic period of ignorance in Arabia, marked by many moral vices.
Explanation:During Jāhiliyyah, vices such as idolatry, tribal pride, alcohol, and injustice were widespread.
Among the options given, vengeance was particularly serious because it led to endless family and tribal blood feuds.
This habitual revenge destroyed peace and delayed any sense of justice in Arabian society.
It was therefore considered the worst moral malady of that era.
Cowardice, disloyalty, and insincerity were also present, but they were not as devastating as constant vengeance.
Answer:D. vengeance