Concept:The extract builds its dominant images around a ship at sea during a violent storm.Explanation:The words “tempest” and “winds” at once bring a storm scene to mind.The phrase “labouring bark” refers to a ship struggling against the waves.Expressions such as “climb hills of seas” and “duck again as low / As hell's from heaven” describe the vessel rising to huge wave-tops and then falling into deep troughs.The “calms” that follow the storm also suggest the quiet after a rough sea voyage.All these pictures together are drawn from the experience of sailing and navigation, not from love, war, or nature in a broad sense.Answer:C. sailing