What is the radian measure of 150°?

Correct answer: \(\frac{5\pi}{6}\)

The governing conversion is \(180^\circ=\pi\) radians. Therefore, to convert degrees to radians, multiply the degree measure by \(\frac{\pi}{180^\circ}\). For 150°, \(150\times\frac{\pi}{180}=\frac{150\pi}{180}=\frac{5\pi}{6}\), after dividing numerator and denominator by 30. Hence option A is correct. The alternatives represent different standard angles: \(\frac{3\pi}{4}=135^\circ\), \(\frac{2\pi}{3}=120^\circ\), and \(\frac{7\pi}{6}=210^\circ\). A reasonableness check also helps: 150° lies between 90° and 180°, so its radian value must lie between \(\frac\pi2\) and \(\pi\); \(\frac{5\pi}{6}\) satisfies that condition.