Let $R$ be the set of real numbers. For every natural number n,
$$\begin{aligned}
& f _ { n } : [ n \pi , ( n + 1 ) \pi ] \rightarrow R \\
& f _ { n } ( x ) = \frac { 1 } { 5 ^ { n } } | \sin x |
\end{aligned}$$
What is the sum of the areas of the regions between the functions defined in this form and the x-axis in square units?\\
A) $\frac { 7 } { 5 }$\\
B) $\frac { 8 } { 5 }$\\
C) $\frac { 9 } { 5 }$\\
D) $\frac { 3 } { 2 }$\\
E) $\frac { 5 } { 2 }$