The correct answer is C) priests are allowed to marry.
The statement that applies to Eastern Orthodoxy and not Roman Catholicism at the same time as the Great Schism is "priests are allowed to marry."
The Catholic Church has never allowed priests to get married.
The Great Schism happened in 1054. This split the Church into two divisions: the Catholic Roman Church and the Eastern Orthodox Church. Many theological and political reasons made the separation inevitable, such as the power of the pope and the Nicenon-Constantinople Creed.