Final answer:
The fishermen and mountaineers should be granted an audience with the King and the Crown Prince due to their historical loyalty and the importance of their message.
Step-by-step explanation:
The passage suggests that the fishermen and mountaineers who have returned from the island and wish to speak with the King are loyal subjects with a strong historical connection to the royal house and the Church. The priest advises that these men should be granted an audience with the King and the Crown Prince due to their loyalty and the significance of their message. Given the context and the implied reverence towards these individuals, the most appropriate action for the King would be to grant an audience to the fishermen and mountaineers, as this aligns with the respect for their loyalty and service.