Sagot :
The split into Sunni and Shia divisions in Islam can be traced to "a
dispute over the question of Muhammad's successor" in the year 632 AD.
Immediately following Muhammad's death, one section of Muhammad's
follower wanted "Abu Bakr", the father of Muhammad's wife "Aisha" to be
the rightful successor of Muhammad, whereas the other sect beleived that
Muhammad divinely ordained (or chosen) his cousin and son-in-law "Ali
Ibn Abi Talib" to be his successor. The sect in favor of "Abu Bakr" are
called as "Sunnis" and the one in favor of "Ali Ibn Abi Talib" were
called as "Shias". This conflict of choice led to a lot of violence at
that time following Muhammad's death and this rivalry or animosity
towards each other continues to this date.
the answer is c. a dispute over the question of Muhammad's successor