What is the radian measure of 15°?

Correct answer: π/12

For degree-to-radian conversion, multiply the degree measure by π/180°. Therefore, 15° × π/180° = (15π/180) radians. Dividing numerator and denominator by 15 gives π/12 radians, so option B is correct. A useful check is that 30° equals π/6; 15° is half of 30°, so its radian measure must be π/12. The distractors represent other standard angles: π/6 is 30°, π/10 is 18°, and π/8 is 22.5°. Keeping the degree symbol in the conversion factor conceptually shows that the degree units cancel and the result is expressed in radians.