Step 1: Find the lines:
Writing in the form $2x + 5y = k$: $L_1$ has $k = 10$ (from $p = 5$). $L_2$ must have the same $x$ and $y$ coefficient ratio, which needs $q = 4$ and gives $k = 20$.
Step 2: Distance via a point:
Take the point $(5,0)$ on $L_1$. Its distance from $2x + 5y - 20 = 0$ is $\frac{|10 - 20|}{\sqrt{29}} = \frac{10}{\sqrt{29}}$.
Final Answer:
The distance is $\frac{10}{\sqrt{29}}$, option (A).
\[ \boxed{\frac{10}{\sqrt{29}}} \]