Manufacturers of mechanical pencils make most of their profit on pencil leads rather than on the pencils themselves. The Write Company, which cannot sell its leads as cheaply as other manufacturers can, plans to alter the design of its mechanical pencil so that it will accept only a newly designed Write Company lead, which will be sold at the same price as the Write Company' s current lead. Which of the following, if true, most strongly supports the Write Company's projection that its plan will lead to an increase in its sales of pencil lead? ['A rival manufacture recently announced similar plans to introduce a mechanical pencil that would accept only the leads produced by that manufacturer.', 'First-time buyers of the mechanical pencils tend to buy the least expensive mechanical pencils available.', 'A Write Company executive is studying ways to reduce the cost of manufacturing pencil leads.', 'In extensive text marketing, mechanical-pencil users found the new Write Company pencil markedly superior to other mechanical pencils they had used.']