His daughters – Q3
Uthman ibn Affan (may Allah be pleased with him) was known as Dhul-Nurayn (the man of the two lights) because he married two daughters of the Prophet (peace and blessings be upon him) in succession: Ruqayyah and Umm Kulthum (may Allah be pleased with them). (Reference: “al Fusool fi Seerah ar-Rasool” Ibn Kathir)