Final answer:
The other slave in Medea's household, besides Medea herself, is the Nurse, who is depicted as a caretaker and confidante within the family.
Step-by-step explanation:
The question is asking about another slave in the household of the character Medea from Greek mythology. Looking at the characters provided, Jason is not a slave; he was Medea's husband who deserted her. Creon is a king, not a slave, in the Medea narrative. Glauce is the daughter of Creon, to whom Jason leaves Medea for, and is not a slave.
The correct answer is the 4) Nurse, who is a member of Medea's household and is often seen in ancient Greek tragedy as a slave or old servant who has been with the family for a long time. In the play 'Medea' by Euripides, the Nurse serves as a key confidante and caretaker figure within the household, fulfilling the role of a slave in her capacity.