To convert degrees to radians, you can use the conversion factor \(\frac{\pi \text{ radians}}{180^\circ}\).
For 72 degrees:
\[ 72^\circ \times \frac{\pi \text{ radians}}{180^\circ} = \frac{72\pi}{180} = \frac{2\pi}{5} \text{ radians} \]
Therefore, the correct answer is:
\(\frac{2\pi}{5}\) radians.