This particular excerpt makes part of the bigger poem "The Tide Rises, The Tide Falls", written by Henry Wadsworth Longfellow between 1807 and 1822. In essence, this particular poem makes reference to the process of life, death and rebirth, through the image of the ocean, its movements, its activities and its effects on life. The poem is short, only three stanzas long, and most of it shows the sadness of life as it comes and then ebbs away, marking with it the time limitation on life.
In this particular excerpt of the poem, Longfellow is making reference to how natural events, like the flow of the sea, affect human beings, their lives, and links the two things, human life, and nature, by giving an almost human characteristic to the ebb and flow of the sea. This is why, the correct answer here is B: Human beings are challenged by events in the natural world.
