Answer: D.After the shipwreck, Crusoe realizes that if the crew had stayed on the ship instead of fleeing on lifeboats, they would have all been saved.
Situational irony is a literary device in which actions have the opposite effect from what was intended. It describes a situation in which we encounter incongruity between expectations and outcome.
In this case, the crew had wanted to survive, so they decided to flee on the lifeboats. The irony is that the crew perished because of this decision, when they would have survived if they had stayed in the boat.