GWD-24-Q 22:想了很久没弄明白~忘帮忙~~many thanks~!

GWD-24-Q 22:

Often patients with ankle fractures that are stable, and thus do not
        require surgery, are given follow-up x-rays because their orthopedists
        are concerned about possibly having misjudged the stability of the fracture. When a number of follow-up x-rays were reviewed, however, all
        the fractures that had initially been judged stable were found to have
        healed correctly. Therefore, it is a waste of money to order follow-up x-rays of ankle fracture initially judged stable.

Which of the following, if true, most strengthens the argument?

A.      Doctors who are general practitioners rather than orthopedists are
        less likely than orthopedists to judge the stability of an ankle fracture correctly.

B.       Many ankle injuries for which an initial x-ray is ordered are revealed
        by the x-ray not to involve any fracture of the ankle.

C.      X-rays of patients of many different orthopedists working in several
        hospitals were reviewed.

D.      The healing of ankle fractures that have been surgically repaired is
        always checked by means of a follow-up x-ray.

E.       Orthopedists routinely order follow-up x-rays for fractures of bone
        other than ankle bones.

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the OA is C

但是我不清楚怎么解释这两者之间的关系..为什么就加强了呢？

many thanks~!