To solve the equation \( \frac{1}{\frac{1}{5}} \), you can simplify it.
The fraction \( \frac{1}{\frac{1}{5}} \) is equivalent to multiplying by the reciprocal of \( \frac{1}{5} \):
\[ \frac{1}{\frac{1}{5}} = 1 \times 5 = 5 \]
So, the answer is C. 5.