How many major dynasties were in power following muhammads death

After Muhammad's death in 634, there were four caliphs later referred to by the Sunni as "rightfully guided," who succeeded Muhammad. However, from 656 there were conflicts over succession, and two civil wars (656-661 and 680-692) broke out within the community of Muslims.

After Muhammad's death in 634, there were four caliphs later referred to by the Sunni as "rightfully guided," who succeeded Muhammad. However, from 656 there were conflicts over succession, and two civil wars (656-661 and 680-692) broke out within the community of Muslims.

sorry i do not know this

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering