What Was the Principle of Succession Within the Ottoman Empire

What was the principle of succession within the Ottoman Empire?

A) Like earlier Islamic dynasties, the Ottoman Empire lacked a principle of succession, a fact that led to protracted warfare among prospective successors.
B) Succession within the Ottoman Empire was based on primogeniture, that is, the oldest son automatically succeeded the previous sultan.
C) Like the early Islamic administration of the orthodox caliphs, the successions within the Ottoman Empire was elective.
D) Ottoman sultans selected their successors prior to their death and elevated them as co-rulers.