Answer:
Correct answer is d. series of rulers from the same family.
Step-by-step explanation:
Option D is the correct, because dynasties are established inside a certain family. The continuation of the dynasty was usually established by the creation of the line of succession. Usually, especially in the Middle Ages the rule of primogeniture existed. According to it, the oldest son was inheriting the throne, but there are a lot of examples that it wasn't always like that.
For example Henry VIII was inherited by his daughters.