The first one is the answer ;)
1) They mostly spread Islam through conquering new countries. What they did also was unite all people under a single rule and ended religious uprisings.
2) There was tensions because one faction believed that Muhammad should be succeeded by someone chosen by people, while the other faction believed that his successor should be someone from his bloodline.
Scarlett letter
there its a book dedicated to the story
Reform=political or social change
Abolition=the formal end of something, such as slavery
Strike=when the members of a union stop work as a way to pressure change
Collective bargaining =negotiations between workers and employers
Suffrage= right to vote
As just as fair would be your answer because the others all talk about one road being better or worse in a way but fair basically is used as equal.