To the best of my knowledge it's A
The religion splitting into two major branches, the shiite and the sunni.
A money economy begin to replace the barter economy in the high middle ages because : B. as trade expanded to cover greater distances, a unit of exchange became more important
During formal discussion, mental notes could help you maintain your focus/attention for the point that given by another speaker so you could give your opinion or counter argument later.
This will give the impression that you're an attentive and a competent person.
