PT 7 S4 Q17

Since the introduction of the Impanian National Health scheme, Impanians ... ...

Which one of the following, if true, does most to explain the apparently paradoxical outcome?
(A) The National Health scheme has greatly reduced the number of medical claims handled annually by Impania's private insurers, enabling these firms to reduce overhead costs substantially.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Resolving & Explaining: Intro Set