The two men crawled across the sun scorched sand. The wind blew the sand grains into their faces at blinding speeds as they reached their way over the dune. The man in back asked the other man to stop, but his throat was so dry that the word sounded more like "top." So the other man continued. As they reached the top of the dune, they looked over and saw a glistening pool some thirty yards down the hill. It wasn't a large pool, but it shimmered in the sun, beckoning the dehydrated men. It urged them to continue their struggle. The men summoned the will to live. They used it as strength when they had none, and the men pushed forward until the tiny pool was in reach. The man in front desperately scooped a handful of the shimmering liquid into his mouth. Instantly he began coughing and spitting out the water. The man behind him seemed confused, until the man in front said, "This is salt water..."

Is this Verbal, Situational or Dramatic Irony?