The main difference between the eastern and western churches in this context is that eastern churches allowed priests to marry, while western churches typically required celibacy among priests.
To clarify the other options:
- Conducting services on Sundays: Both eastern and western churches conduct services on Sundays.
- Use of Latin in services: Latin was primarily used in the western church (Roman Catholic Church) and is not the case in the eastern churches (Eastern Orthodox and others), which typically use their local languages or Greek.
- Use of religious icons: Eastern churches (especially Eastern Orthodox) place a strong emphasis on the use of religious icons, while the western church had a more varied approach, particularly during the Reformation.
So, the correct answer regarding what the eastern churches allowed that the western churches did not is "priests to marry."