Step 1: Converting degrees to radians.
The formula to convert degrees to radians is:
\[
\text{Radian measure} = \text{Degree measure} \times \frac{\pi}{180}.
\]
Step 2: Apply the formula.
Substitute 520° into the formula:
\[
\text{Radian measure} = 520 \times \frac{\pi}{180} = \frac{520\pi}{180} = \frac{25\pi}{9}.
\]
Step 3: Conclusion.
The correct answer is (A) \(\frac{25\pi}{9}\).
Final Answer:} \(\frac{25\pi}{9}\).