How did the various achievements and policies of muhammad’s successors the arab world to grow?

There are many ways the policies and achievements of Muhammad's successors helped the Arab world. One of the main achievement was to unite the Arab under one flag instead of various tribes and communities, as the successors of Muhammad used the term "Khalifa" which was considered a unanimous leader of all the Muslims thus any territory that came under Islamic rule or any people who accepted Islam were united behind "Khlifa" instead of various leaders and tribal heads.
As there was a central system established in that time of succession, more focus was placed on developmental structures. For example in the time of Umar, the second successor various facilities were built for the travelers and those out on the road.
Trade and commerce evolved due to peace and stability provided by the central government as opposed to earlier times when caravans were looted in other tribal territories. 

pacal the great: the throne was passed on to pacal through a female; as a result, he believed that he must legitimize his claim to the throne to add stability to his reign.

as a result, the daughter of ac kan's brother ruled until her son, pacal, reached an age old enough to assume the throne.

pacal the great became the king of the mayan city of palenque in a different way than most mayan kings.

pacal pointed out that ac kan had succeeded his mother as ruler, thereby establishing a precedent for the rule to pass through a female.  

he tried to justify that the way he gained the throne by connecting his mother with the divine mother and the mythological events that happened during the creation of the world.  

typically, the son of a male mayan ruler inherited the throne, but in 612 ce, king ac kan died and did not leave behind a male heir.

montezuma 1: even so, these wars of conquest failed to provide enough human sacrifices and because of this, he formed a triple alliance with cities in the valley of puebla-tlascala.  

in addition, montezuma realized that his government failed to the aztecs during the famine.

in order to appease him, montezuma increased the number of human sacrifices.

the aztec performed human sacrifices to their god huitzilopotchli because they believed he desired human blood.  

around 1440 ce, montezuma i became the fifth emperor of the aztecs and went on to rule for 28 years.  

soon after he assumed the throne, the aztecs were hit with a series of disasters, namely a plague of locusts, a flood, and a harsh frost  

huayna capac: huayna capac also fought to gain territories north of his empire in what is now ecuador.  

huayna capac significantly extended the inca empire to the south, into what is now argentina and chile.  

in 1493 ce, huayna capac became the eleventh ruler of the inca empire.  

huayna, therefore, wanted to gain his own lands and launched campaigns against tribes to the east and north of the empire.  

the inca empire reached its peak under the rule of huayna capac.

during this time the empire covered a vast territory including parts of present day colombia, peru, argentina, chile, bolivia, and ecuador.

during his reign, huayna heard about bearded men with pale skin that resembled the incan1 god viracocha and took this news as a bad omen.

huayna took this as another bad omen that predicted the destruction of the empire.

the answer is a. laws were enacted in the aftermath of the plot to make it harder to free slaves,increasing sectionalism