单项选择题

  Line      Because the framers of the United States
            Constitution (written in 1787) believed that protecting
            property rights relating to inventions would encourage
            the new nation’s economic growth, they gave
    (5)    Congress—the national legislature—a constitutional
            mandate to grant patents for inventions. The resulting
            patent system has served as a model for those in
            other nations. Recently, however, scholars have
            questioned whether the American system helped
    (10)    achieve the framers’ goals. These scholars have
            contended that from 1794 to roughly 1830, American
            inventors were unable to enforce property rights
            because judges were "antipatent" and routinely
            invalidated patents for arbitrary reasons. This
    (15)    argument is based partly on examination of court
            decisions in cases where patent holders ("patentees")
            brought suit alleging infringement of their patent
            rights. In the 1820s, for instance, 75 percent
            of verdicts were decided against the patentee.
    (20)    The proportion of verdicts for the patentee began to
            increase in the 1830s, suggesting to these scholars
            that judicial attitudes toward patent rights began
            shifting then.
              Not all patent disputes in the early nineteenth
    (25)    century were litigated, however, and litigated
            cases were not drawn randomly from the
            population of disputes. Therefore the rate of
            verdicts in favor of patentees cannot be used
            by itself to gauge changes in judicial attitudes
    (30)    or enforceability of patent rights. If early judicial
            decisions were prejudiced against patentees, one
            might expect that subsequent courts—allegedly
            more supportive of patent rights—would reject
            the former legal precedents. But pre-1830
    (35)    cases have been cited as frequently as later
            decisions, and they continue to be cited today,
            suggesting that the early decisions, many of
            which clearly declared that patent rights were
            a just recompense for inventive ingenuity,
    (40)    provided a lasting foundation for patent law.
            The proportion of judicial decisions in favor of
            patentees began to increase during the 1830s
            because of a change in the underlying population
            of cases brought to trial. This change was partly
    (45)    due to an 1836 revision to the patent system:
            an examination procedure, still in use today, was
            instituted in which each application is scrutinized
            for its adherence to patent law. Previously,
            patents were automatically granted upon payment
    (50)    of a $30 fee.   The author of the passage cites which of the following as evidence challenging the argument referred to in lines 14-15