I would say logically wise, unless this is apex its going to be c and b if its only one, i would say b.
There's three possible answers I found. The first one being that they worked in a bike shop, the second is that they were self taught, and the third is that there was this guy named Charlie Taylor who worked for them and he pretty much built the engine of their first planes
The split into Sunni and Shi'a Islam can be traced to the death of the Prophet Muhammad when it was decided who would become the next leader of the Islamic community. The Sunni sect believed that the Islamic community would choose the next leader where as the Shi'a believed the next leader would be a descendant or family member of the Prophet.
