Final answer:
Ralph in 'Lord of the Flies' believes that keeping a signal fire going is the most crucial task for the boys, as it represents their best hope for being rescued and returned to civilization.
Step-by-step explanation:
According to Ralph, the character from William Golding's novel 'Lord of the Flies', the most important thing the boys should be doing is maintaining a signal fire. Ralph emphasizes the importance of the fire as their main hope for rescue, understanding that without it, the chance of being spotted by a passing ship or airplane would be significantly reduced. Despite the many distractions and conflicting priorities that arise among the boys on the island, Ralph persistently argues that the fire is the key to their survival and eventual return to civilization.