Answer:
B. Its end marked the start of the split between the Eastern and Western Churches.
Step-by-step explanation:
The Iconoclast Controversy was a dispute in the Byzantine Empire over the use of religious icons in the 8th and 9th centuries. The controversy pitted those who supported the use of icons (iconodules) against those who opposed it (iconoclasts). The controversy had significant religious and political implications, as it challenged the authority of the emperor and the role of the Church in the Byzantine Empire.
The controversy came to an end in 843 AD with the restoration of the use of icons, which was celebrated as the Feast of Orthodoxy. However, the controversy had already caused a deep divide between the Eastern and Western Churches, which would eventually contribute to the Great Schism of 1054 AD and the permanent split between the Eastern Orthodox Church and the Roman Catholic Church.
Therefore, the end of the Iconoclast Controversy marked the start of the split between the Eastern and Western Churches, making option B the correct answer.