Answer:
C). To find
Explanation:
Context clues are defined as the hints or clues that the author provides to assist the readers understand the meaning of an unfamiliar word. These clues usually found surrounding or near the unfamiliar word to promote readers' comprehension.
In the given sentence, the word 'unearth' means 'to find' as the treasure has been dug deep in the sand and it will take the complete day to find it from the sand as they do not where and how deep in the sand it exactly would be found. Thus, option C is the correct answer.
