According to the passage, which of the following reasons why only the most determined trav

According to the passage, which of the following reasons why only the most determined travelers can see the best of the national parks is NOT mentioned？

A．Infrastructural development in these areas is limited.

B．The ski resorts do not have the same number of lifts as their European counterparts

C．Roads are of poor quality in the south.

D．The mountains are too tall for the tourists to clim

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