The prophet Muhammad was born in Mecca. Muslims believe the Quran derived from revelations given to Muhammad from the angel Gabriel. As he gained followers, Muhammad found he had to flee Mecca for Medina. By 629, Muhammad had gained authority over both Mecca and Medina, both of which are considered holy cities within the Islamic faith. Note that Jerusalem, Karbala, and Najaf are all holy cities within Islam, but not as pivotal as Mecca and Medina throughout the entire faith.

An extremely violent and unstable period in the history of Feudal Japan, the Sengoku Period began with the end of the Onin War in 1467, and ended in 1603 when the Tokugawa Shogunate consolidated power. 

The Sengoku period lasted for nearly 150 years, ending with the rise of the Tokugawa Shogunate in 1603.

In Feudal Japan, the political power lay with the shoguns, who were similar to military dictators. The emperor was a figurehead who had no rule power. The samurai were the warriors of the shoguns, similar to European knights. The merchants were the lowest class, because the Japanese saw the occupation of buying and selling as distasteful.

A Bugyo was an appointed position, held by Samurais. They were responsible for the general running of cities and regions as well as finance and development. They reported directly to the Shogun. Originally the term only applied to officials who were appointed with a designated task to complete. However, the position was formalized during the Edo period (1603-1868) until eventually there were 36 Bugyo positions in the Japanese bureaucracy. 

Nobunaga (1534-1582) was very interested in European culture and even wore European clothes. He collected western artwork and also encouraged trade with Siam, Indonesia, and the Philippines; countries outside the usual Japanese region of Northeast China and Korea. Moreover, even though the goal of Japanese unification had been apparent for some time, Nobunaga was the first daimyo to make tangible efforts at unification as he unified several provinces in his immediate region and opened trade avenues with the outside world. 

Bushidō differed in that the samurai were not tied to land which they protected as a European knight might do, but were more focused on the protection of their lord, the daimyo. Daimyo were subordinate to the Shogun. Ronin were samurai who had failed to commit seppuku, ritual suicide, and were therefore not serving a lord.

The United States did not exist in the 15th century, so that would not be a good choice. China was ruled by the Ming dynasty for this period and did not experience civil war, so that would not be the best choice. France and Spain did not have a civil war that was known by this name, so they too would not be good answers. Lastly, the War of the Roses was a war of succession over the English throne, so that would be the best answer here.

The Articles of Confederation convened the first government of the future United States, so it would not be the best answer. The Constitution convened the current government of the United States, so that would also not be a good answer to the question. The Upanishads are a religious text from Hinduism, so that would not be a good choice here. Last, the Magna Carta was created in the 13th century and established a constitutional monarchy in England, so that would be the best choice.

The Hundred Years' War was primarily fought in what would later be known as France, although some battles were waged in the Netherlands, Spain, and England. The Norman invasion of England had resulted in generations of land claims between England and northern France. England and France would fight historic battles, including Crecy, Agincourt, and Poitiers, over control of French territory. Truces resulted in England eventually losing ownership of lands in France, while the French countryside was devastated by mercenaries, economic hardship, disease, and starvation.