What does the Hirja symbolize in Islam and what did it start?

A. It means divide and marks the beginning of the Sunni-Shia split
B. It means prophesize and marks the beginning of the Sunnah tradition.
C. It means sacred and marks the beginning of worshipping in mosques
D. It means migration and marks the beginning of Muslim era

D. It means migration and marks the beginning of Muslim era

The Hirja symbolizes the migration of the Prophet Muhammad and his followers from Mecca to Medina in 622 AD. This event marks the beginning of the Islamic calendar and is seen as a turning point in the history of Islam. It also signified the establishment of the first Muslim community and the spread of Islam.