Answer:
A. Roman Catholic churches perform a mass, but Eastern Orthodox churches don't.
Step-by-step explanation:
There are many differences between the Roman Catholic and Eastern Orthodox church, and one of them is that Catholic churches perform a mass, while Orthodox churches do not. They perform liturgies instead of masses.
The rest of the options are incorrect, because:
- The pope heads Roman Catholic churches, while the patriarch heads Eastern Orthodox churches (not the other way around).
- Both churches follow the New Testament.
- Orthodox priests can be married if they got married before being ordained to the priesthood, but they are not allowed to enter marriage after ordination.