Final answer:
One major problem that missionaries encountered in organizing indigenous churches was helping new converts to overcome enmity among tribal groups.
Step-by-step explanation:
One major problem that missionaries encountered in organizing indigenous churches was d) Helping new converts to overcome enmity among tribal groups. This problem arose when different tribes or groups with historical conflicts or animosities converted to Christianity and were expected to come together in one church. Missionaries had to work to promote reconciliation and unity among these groups in order to establish a functioning indigenous church.