Final answer:
Arjun resembles Rukmani's brother, as inferred from the textual context given, although the specific literary work is not provided.
Step-by-step explanation:
To Rukmani, Arjun resembles her brother. This comparison is drawn from the context provided by the quotes where Rukmani's qualities and life circumstances are discussed, along with Arjun's expression of the fame of the royal house of the Kurus. There is no direct reference to point towards Arjun resembling a father, son, or husband.
Thus, the closest answer based on the given textual evidence would be her brother, though without a specific text to draw from, this inference is made with the assumption that the question pertains to a work of literature where Rukmani and Arjun are characters.