Editor: Articles in Gardening Magazine often spur sales of the plants they describe, particularly among people new to gardening. Accordingly, we will no longer publish articles or accept advertisements praising the beauty of rare wildflowers. Most such plants sold to gardeners have been difficult to propagate under cultivation, so plant sellers often collect them in the wild. Our new policy is part of our efforts to halt this yearly plundering of our native plant populations. Which of the following, if true, casts the most doubt on the wisdom of the magazine's new policy as a way of pursuing the intended effect? ['Revenues from sales of plants collected in the wild are supporting the discovery of new low-cost techniques enabling rare wildflowers to be readily propagated in nurseries.', 'When people new to gardening buy plants, they often fail to take adequate care of the plants that they buy and become discouraged from buying those varieties again.', 'The demand for rare wildflowers rarely exceeds the number of such plants that can be collected in the wild by plant sellers.', 'Plant sellers who sell rare wildflowers have no reasonably inexpensive alternative way to offer their wares directly to new gardeners.']