The controversy over the nature of Christ, the relationship between what was human and what divine in Christ caused disputes in the Byzantine world. It weakened permanently the Byzantine society’s cohesiveness. This contributed to weakening of the imperial defenses against the Muslims. The new theological controversies, which ran from the fourth century CE to the late seventh century CE, eventually led to the loss of the eastern provinces of the empire. As for choices B, C, and E, even though the latifundia system worked well at the beginning, it caused the landowners to gain excess power while the number of free military peasants decreased since the latter became serfs to rich land owners. Hence, the military of the empire weakened as soldiers became workers for the rich. The armies possessed by the wealthy posed a threat to the throne. On the other hand, even though Latin was the official language of early Constantinople, as it was of the entire Roman Empire, that language was replaced by Greek after the sixth century CE. Greek, which had long been the vernacular in Constantinople anyway, became the language of government in Byzantium. The Byzantine Empire was profoundly influenced by the Greek language, religious elements, literature and classical culture. As time went by Byzantine scholars and religious figures did not have to, nor did they tend to, learn to read Latin. While Greek culture had been central to the ancient Romans, and while the pagan religion of the Greeks had been adopted almost wholesale by the Romans, as Greek speakers located near Greece, the Byzantines were inspired much more deeply by the philosophy and literature of classical Greece than they were affected by the thinking and writing of classical Rome. Over time, Greek became the main language used. The Byzantines called themselves Romans but the language that was the medium in their empire became Greek. Therefore, although it had begun its work in the Latin language, it moved to Greek without causing major conflicts. The correct answer is D.