Astronomer: Mount Shalko is the perfect site for the proposed astronomical observatory. The summit would accommodate the complex as currently designed, with some room left for expansion. There are no large cities near the mountain, so neither smog nor artificial light interferes with atmospheric transparency. Critics claim that Mount Shalko is a unique ecological site, but the observatory need not be a threat to endemic life-forms. In fact, since it would preclude recreational use of the mountain, it should be their salvation. It is estimated that 20, 000 recreational users visit the mountain every year, posing a threat to the wildlife. Which one of the following, if true, most weakens the astronomer's argument? ['More than a dozen insect and plant species endemic to Mount Shalko are found nowhere else on earth.', 'The building of the observatory would not cause the small towns near Mount Shalko eventually to develop into a large city, complete with smog, bright lights, and an influx of recreation seekers.', 'A survey conducted by a team of park rangers concluded that two other mountains in the same general area have more potential for recreational use than Mount Shalko.', 'Having a complex that covers most of the summit, as well as having the necessary security fences and access road on the mountain, could involve just as much ecological disruption as does the current level of recreational use.']