The correct answer is the following: option d. Using "Polybus' son to refer to "Oedipus" is an example of a patronymic. A patronymic is a word that is used to indicate descent. It can be used as an adjective, like the case of the example provided in the question, "Polybus' son" to indicate the descent of that person. It can also be used as a noun; this is to say like a patronymic name. Examples of this use could be the family name of Williamson, which means the son of William.