The correct answer is A) it marked the beginning of the Islamic era.
The Hijrah was important because it marked the beginning of the Islamic era.
Hijrah is an important element in the foundation of Islam. In 622, it was the pilgrimage of Muslim Prophet Muhammed from Mecca to the city of Medina. He left Mecca over the persistent rumors that some wanted to assassinate him. Historians agree that this trip represented the beginning of the religion known as Islam.