Final answer:
Nathan's surprise at Rukmani's arrangements for Ira's wedding could stem from a variety of reasons related to conflicts in unilineal societies, such as issues with the dowry or the wedding arrangements.
Without explicit information from the book, the exact reason for his surprise cannot be determined from the provided options.
Step-by-step explanation:
The reason Nathan is surprised at Rukmani's arrangements for Ira's wedding is not explicitly stated in the question. However, given the context provided about the possible areas of conflict that can arise from marriage arrangements in unilineal societies, such as issues surrounding bride wealth, bride service, economic challenges, and family expectations, one could infer that Nathan's surprise could be related to any disparity or issues arising from these areas.
For instance, if the dowry arranged by Rukmani was too small or too large, it could lead to feelings of inadequacy or conflict. Similarly, if the wedding arrangements were deemed too elaborate compared to what the husband's family could offer, it might lead to tension and surprise on Nathan's part.
In the absence of the information directly from the source material, which is typically required for literature-related questions, an accurate choice among the provided options cannot be made.
He could be surprised due to any of the possible conflicts arising from bridewealth and bride service obligations mentioned, but without the specific details from the text, it would be speculative to choose an option like the dowry being too small, the wedding being too elaborate, the groom being unsuitable, or the marriage being an inter-caste marriage.