I believe the answer is: how leadership should be passed down
Sunni Muslim beleived that all people can be appointed into leadership as long as they do not violate the core rule held in Muslim belief. The Shi'ite on the other hand believe that the only people that could be elected as leaders are the descendants of Muhammad.
The answer is option D "how leadership should be passed down." Muslims believed that anyone can rise to the power as long as they don't break any of their rules, and beliefs. Many people disagreed with this belief because people thought that themselves as people should elect the leader.
Hope this helps!
