Answer:
C. A split within the church resulted in the creation of two separate churches.
Step-by-step explanation:
In the year 1054, the Patriach of Constantinople was excommunicated by the Pope. This is know as the West-East schism, and led to the division of the church, which was up until that point unified, into two different branches: the Western Branch, led by the Pope in Rome, and the Eastern Orthodox branch, led by a Patriach in Constantinople.
With time, the Eastern Orthodox church further subdivided with other branches in Athens, in Moscow, etc, although it remains, up to this day, more or less unified.