Convert 345° into radians.

Correct answer: 23π/12 radians

The governing conversion relationship is 180° = π radians. Hence a degree measure is converted to radians by multiplying by π/180. For 345°, the calculation is 345 × π/180 = (345/180)π. Dividing numerator and denominator by 15 gives 23π/12 radians, so option C is correct. A magnitude check also supports this result: 345° is only 15° less than 360°, so its radian measure should be slightly less than 2π; indeed, 23π/12 = 2π − π/12. Option A equals 330°, option B equals 285°, and option D equals 315°, so none of those represents 345°.