In Ponniyin Selvan, Kundhavai sends a message through Vandhiyathevan telling Arulmozhivarman to return to Palaiyarai immediately. This message is crucial to the plot - it summons Arulmozhivarman back from Lanka, setting in motion key events. Option A (accepting Lanka's throne) and C (staying in Lanka) would mean continuing his stay there, which contradicts the message.