Opponents of peat harvesting in this country argue that it would alter the ecological balance of our peatrich wetlands and that, as a direct consequence of this, much of the country' s water supply would be threatened with contamination. But this cannot be true, for in Ireland, where peat has been harvested for centuries, the water supply is not contaminated. We can safely proceed with the harvesting of peat. Which one of the following, if true, most strengthens the argument? ["The peat-harvesting industry of Ireland has been able to supply most of that country's fuel for generations.", 'The original ecology of the peat-harvesting areas of Ireland was virtually identical to that of the undisturbed wetlands of this country.', 'Over hundreds of years, the ecological balance of all areas changes slowly but significantly, sometimes to the advantage of certain flora and fauna.', 'The activities of other industries in coming years are likely to have adverse effects on the water supply of this country.']