GRE General Test: RC-606927 GRE Reading Comprehension

It is very hard to prove or disprove the existence of the Loch Ness Monster because of the characteristics of the very loch that it supposedly inhabits. Loch Ness has cold, murky waters that yield almost zero visibility, a surface area of almost 22 square miles, and depths approaching 1,000 feet. Though the oldest reference to the monster can be traced back as far as 565 ce, the present incarnation of "Nessie" first caught the modern public's eye in April of 1933, shortly after local hotel owners Mr. and Mrs. John Mackay reportedly spotted, in their own words, "an enormous animal rolling and plunging." They detailed their incident to the Inverness Courier, and suddenly the Loch Ness monster was plucked from historical obscurity to be reborn in the pages of the world news. Since then there have been innumerable hoaxes, unexplained sightings, and serious scientific investigations that have turned up some interesting, yet inconclusive evidence. Recently, after the most technologically advanced search to date, a group of researchers working for the BBC concluded that the creature simply does not exist. But the daunting evidence of the researchers has seemingly not deterred the legions of tourists and part-time Nessie hunters. Apparently, as long as the slightest possibility of Nessie being real has existed, the hotels around the Loch, as they have been since 1933, will be full of intrigued souls hoping to catch just a glimpse of a real-life monster.
It can be inferred from the passage that the only way the mystery of the Loch Ness Monster will be solved is if