Why did Shia Muslims believe it was important for Ali ibn Ali Talib to become Mouhammed’s successor?

Shia Muslims believed it was important for Ali ibn Ali Talib to become Muhammed’s successor because he had been appointed by divine instruction. The choice Sunni Muslims made reflected their acceptance of free will that conflicted with Shias strictly obliged nature to Allah. In the Qur’an Muhammed said, “Whoever disobeys me has indeed disobeyed Allah”, Shia Muslims believed the family line was the only moral option.